Sony PDP-01 Plasma Training

Training Manual

Course: PDP-01

Plasma TelevisionModels: KE-37XS910

KE-42XS910KE-50XS910KDE-42XBR950KDE-50XBR950KDE-61XBR950

Diagnostics and Troubleshooting

KE-61XBR950

Table of Contents

Introduction...........................................11. Plasma Panel Troubleshooting ....3Overview ................................................................. 3Pixel Control ........................................................... 4

Plasma Panel Troubleshooting ............................ 4

2. Troubleshooting theKE37/42XS910 .....................................13Overview ................................................................ 13

Signal Processing ................................................ 13The Plasma Panel ................................................ 15Troubleshooting ..................................................... 17Disassembly .......................................................... 26

3. Troubleshootingthe KE50XS910 ....................................37Overview ................................................................ 37Signal Processing ................................................ 37

The Plasma Panel ................................................ 39

Troubleshooting ..................................................... 41Disassembly .......................................................... 52

4. Troubleshooting theKDE42/50/61XBR950 ..........................64Overview ................................................................ 64Plasma Panel Block Diagram ............................. 64

Troubleshooting ..................................................... 66Disassembly .......................................................... 72

5. Disassembling theKDE61XBR950 .....................................79Overview ................................................................ 79Disassemblyling the KDE61XBR950 ................ 79

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PDP-01 - Introduction


Plasma display devices are becoming the choice of many consumers, as evidenced by the amount of thisproduct on the display floor of any electronics goods store and the increasing number of sale ads. Although stillrelatively high in price when compared to other display devices such as CRT and LCD, the gap is rapidly narrowing.The appeal of owning a futuristic “flat” television that can be configured to virtually any installation layout keepsthe demand for plasma growing every year. Geometric distortions, beam landing errors and convergence issuesare non-existent. The narrow viewing angle of rear-projection televisions is also overcome.Although one would normally think of plasma devices as relatively new in the display market, the technology isnot new. Development of plasma-type displays began in 1971 using a monochrome platform. Color displaysbegan to appear in the early 1980s. New developments in panel designs have increased the brightness, resolutionand contrast, along with greater longevity in panel life. Claims of 60,000 hours of useful brightness are beingheard, equating to about ten years of normal viewing time.

The amount of research and development, along with highly sophisticated manufacturing processes are whatkeep plasma displays in the relatively high price range. This factor gives the product great viability in the serviceindustry. The complex circuitry, however, requires today’s technician to keep abreast on these changes indisplay methods to remain competitive. The purpose of this manual is to help the technician better understandthis technology to accomplish this.

Once of the unique aspects of these display devices is the modular construction of the unit itself. The abundantuse of LSI devices, along with a greater demand for on-site repairs, requires that technicians perform mostrepairs at board level. The glass-plasma panel itself can be replaced in about the same amount of time asreplacing picture tubes in a CRT projection set if being done for the first time. Once you become familiar with theprocedure and the chassis, the time will become even less due to the lack of extensive alignment proceduresrequired in CRT sets.

This course is written with a primary emphasis on practical troubleshooting approaches to plasma-type displaydevices, particularly the 2003/2004 models introduced by Sony. In-depth theory will not be discussed. If basicplasma theory is desired, refer to training manual TVP-13.

The technician merely needs to learn the basics of plasma technology, particularly how the panel is controlled, inorder to appropriately diagnose the point of failure. This will require a fresh, new approach in responding to whatmay or may not appear on the screen. Self-diagnostic circuits also provide a valuable tool in isolating a particularfailure. Knowledge of the basics and practical approaches presented in this manual should convince mosttechnicians that servicing plasma displays is no more difficult than any other display device.

This manual will cover six different models ranging from 37" to 61". The model series includes the XS910(available in 37", 42" and 50"), and the XBR950 series (available in 42", 50" and 61"). There are several distinctionsamong these models. The XBR series uses a separate media box to receive ATSC and NTSC broadcasts andcable DTV signals along with analog and digital inputs, making them a true “High Definition” television. TheXS910 series does not have a media box. It has a built-in NTSC tuner and relies on external devices to supplystandard and high definition signals. These types of televisions are known as “High Definition Ready”.

From a repair standpoint, the key difference among each model is the design of the plasma panel. Four differentdesigns are used. In attempting to cover such a large variety of designs, this manual will be arranged so thatbasic panel operation and troubleshooting is covered first. Even though there are different panel designs, theunderlying concept of controlling a plasma panel is universal among them. Understanding how the panel iscontrolled is important for troubleshooting purposes. The remaining task is identifying the boards and theirnomenclature. Once this is clear, it is only a matter of becoming familiar with the unique layout of the differentpanels. The subsequent chapters will cover each model based on its panel usage along with procedures andtips to aid in properly servicing the specific design.

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Detailed procedures will also be covered for the proper disassembly, re-assembly and adjustments (if required).The first item the technician will notice is that plasma televisions use a large number of screws. Removal of therear cover can involve up to 60 screws of varying type and size. Many other screws are used for shielding andpanel support brackets, not to mention circuit board mounting. It is important to return all screws to their originallocation. Placement of all wires is also crucial for minimizing signal interference and to prevent damage to wiringwhen re-assembling the unit. This is especially true when installing support brackets and the rear cover.

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1. Plasma Panel Troubleshooting

Chapter 1 - Plasma Panel Troubleshooting

HV OR Y SCANBOARD

COMMONOR

X SCANBOARD

DATA OR ADDRESS BOARD

LOGIC CONTROL BOARD

RGB DATA

FIGURE 1-1 BASIC PLASMA DISPLAY CONTROL PDP01.1-1 3/23/04

SECOND ADDRESS BOARDS FOR DUAL SCAN

PLASMA DISPLAY PANEL

OverviewLCD and plasma display devices are similar in how they control light output from a particular pixel. Although theyeach generate a source of light in a different manner, the use of horizontal and vertical control grids allows fortiming a particular pixel for display.In Figure 1-1, a typical layout for a plasma display panel is shown. The horizontal control lines (usually referredto as scan control lines) determine which horizontal line of red, green and blue pixels will be ready to be activatedat a particular time. High voltage pulses of up to 230 volts are sent to the scan lines. Notice the use of separateX and Y driver boards. Each board handles every other scan line. Working in unison, the odd and even scanlines are energized with alternately phased pulses to place the plasma chambers in a “sustain” condition.

The Y-Drive (or High Voltage) board sends scan-drive pulses to a group of drive ICs since the initial charging foreach scan requires the most power. These ICs are mounted on separate circuit boards (usually two) or directlyonto the flexible PC cable molded into the panel, depending on the design. The X-Drive board connects to thepanel without drive ICs since its primary function is to reverse the plasma chamber charge.

The moment a certain horizontal row of pixels is activated, the appropriate intersecting, vertical control linesdetermine which pixels will light. These are known as address or data lines. All of this is timed by a logic controlcircuit (sometimes referred to as a digital board) that receives the incoming digital RGB signal and allocates theinformation to the appropriate pixel. This forms a grid pattern to control each intersecting point. It is a simpleconcept and the understanding of this sequence is critical to analyzing any abnormalities noted on the display.

Some panel designs use addressing lines at the top and bottom of the panel. This is known as a dual-scan andis found in newer panel designs, particularly in larger ones. The amount of addressing control is shared so thatonly half of the vertical distance of the screen is controlled by each of the upper and lower addressing line inputs.

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FIGURE 1-2 - PLASMA CELL STRUCTURE

SUSTAIN ELECTRODE(TRANSPARENT)

SCAN ELECTRODE(TRANSPARENT)

FACE PLATE

ELECTRICLAYER RIB

PHOSPHOR (GREEN)

PHOSPHOR (RED)

DATA ELECTRODE

PHOSPHOR (BLUE)

PROTECTIONLAYER

BACK PLATE

PDP01.1-2 3/1/04

DISCHARGE

Pixel ControlLighting a PixelIn Figure 1-2, a simplified layout of a plasma discharge chamber is shown. Inert gases (usually xenon and neon)are exited by an electrical charge. In order to sustain this state, the electrical charge must be constantly changing.As mentioned previously, the X and Y drivers send alternating pulses to accomplish this. This voltage is at a levelnear the required amount to “excite” the gasses by introducing free electrons. The address lines apply thenecessary voltage to complete the “firing” of the plasma material. This phenomenon causes a release of ultravioletlight.

Each plasma gas chamber resides over a particular red, green or blue phosphor stripe applied vertically on thepanel. By controlling the amount of UV radiation from the plasma chamber across each vertical stripe, colorimages can be displayed with great accuracy.

Creating a PictureReferring back to Figure 1-1, the scan lines determine which pixel row is active at a given time. The electrodesof the scan control lines are transparent, allowing the light from each phosphor stripe to emit from the panel. Theaddress lines work in a unique method to control light output from each pixel.

Whenever a particular scan line is active, the address lines will determine which pixel along that line will light.This is done eight times for each field of video information and is controlled by an 8-bit data word. These arecalled sub-fields. Unlike CRT displays, which are controlled by varying the level of electron beam emissions,each pixel is controlled eight times at 256 possible levels. The more times a particular pixel is fired during thesub-field scan period, the brighter the pixel. If the incoming video signal is sampled at a 10-bit rate for each of theRGB components, a color combination of 700 million is achieved!

Plasma Panel TroubleshootingGeneralDue to the use of different display panel designs, this chapter of the manual will attempt to cover troubleshootingtechniques universal to plasma displays. Differences among the panel designs will only require separate boardlayouts and disassembly procedures. These differences will be covered in the chapters to follow.The first critical item to determine is whether the display panel is the cause of the defect. In most cases, it is quiteevident if the panel is the cause. Other failures may not be so obvious. The main reason for eliminating a fault

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in the panel is to prevent wasted time. A complete disassembly of the unit is required to access the various circuitboards and flexible cables for further diagnosis and visual inspection. This is very time consuming. Plasmapanel failures are not common and most are caused by improper handling and shipping damage resulting incracks to the glass envelope and the release of the internal gasses. They are also quite expensive and, therefore,not something that should be replaced needlessly.

The use of scan, addressing and timing pulses can produce interesting symptoms on the display. Single lines,vertically or horizontally, may be lit when they are not supposed to be. Entire halves or quadrants of the screenmay be lit bright white or appear completely dark. Failures on the logic control board or distortions and leveldrops of the scan pulses produce a myriad of rainbow color effects. The panel may not display any video at all.

The remainder of this chapter will attempt to cover the various symptoms that can develop with each particularcircuit or panel defect. Once again, keep in mind that in most cases the panel itself is usually not the cause of thedefect. There are some panel designs that have driver components mounted directly to the flexible cablesencased within the glass assembly and this would force a replacement of the panel.

NOTE: Due to the complex digital processing involved with plasma displays, unusual symptoms may appear onthe screen that may make it difficult to determine the failure. Always check the Sony Service website at HTTP://service.sel.sony.com for any FPR or service bulletins that may be present regarding the model you are about toservice. An abundance of information is located on the ESI site and is updated daily. Do this before going on theservice call to minimize the amount of time needed to complete the repair.

Troubleshooting a “No Display” ConditionThis tends to be the most difficult symptom to approach since there are many potential sources to prevent thepanel from going active. Failures of any number of B+ lines, the scan and address drivers, or a loss of videoinformation could be the cause. In the case of B+ lines, most units will go into protect shutdown and may noteven generate indications of having done so. There is, however, one important observation that can assist inisolating the panel and/or drivers as the cause.A unique phenomenon occurs whenever a plasma display is powered up. It is known as “priming”. Priming isperformed by the scan drivers. A large positive and negative pulse is sent to each X and Y scan-line at initial turn-on. Residual charges in each pixel are cleared along with the necessary boost to begin discharging from thegasses. Once the pixels are primed, they will continue to discharge a small amount of light, known as “sustaining”.This generates a raster similar to that found on CRT devices although it is lower in level and lacks scan lines. Itis easier to detect in low ambient light conditions. The easiest way to identify pixel lighting is to observe thescreen while turning the unit on and off. With the unit off, you have an idea of what “true black” is. If the pixelsare lighting, you will see the difference between the true black and “reference black”. The use of a magnifyingglass (such as those used for beam landing on a CRT) helps to see if the pixels are emitting light at a low level.

This is an important function to verify. It tells you the panel is functioning and the scan and addressing pulses arepresent along with all of the necessary B+ voltages. It usually indicates a loss of video signal data entering thelogic board and troubleshooting should focus on the video processing circuits rather than the panel and driverassembly. It is possible that a failure could have occurred on the logic board but this is unlikely.

The absence of priming or sustaining a raster brings the focus of troubleshooting to the panel and associatedcircuits to drive it. If the plasma panel’s glass envelope is compromised, allowing the escape of the gasses andthere is no evidence of breakage, it becomes necessary to check for the presence of scan and addressingpulses to isolate the failure to the panel or driver circuits. The means to accomplish this varies between paneldesigns. They will be covered in the chapters of this manual pertaining to each model.

If an oscilloscope is available, scan-pulses can be verified by connecting to the inputs of the scan driver board(s).These boards are easily identified by their location on the side of the panel. Figure 1-3 shows a typical scan-driver layout. There will be one or two boards with several IC drivers. The driver boards will be connected to a

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FIGURE 1-3 - TYPICAL SCAN DRIVER LAYOUT PDP01.1-3 3/1/04

CHECK FOR PULSES ATINPUT PINS

scan generator known as a Y-SUS or High Voltage board depending on the panel design. Placing a scope probeon the pins of the connector to the scan drivers will display high-voltage pulses around 230VPP at about 4µs induration. If these pulses are present, the panel should be priming the pixels. If priming is not occurring, there isa possibility of a compromise in the panel glass.

Distortions in the Display VideoAs mentioned earlier, distortions displayed on the screen will present new and sometimes interesting patternsthat will be unfamiliar to most television technicians. Like CRT displays, however, the symptoms on the screengive excellent clues as to where the problem may lie. CRT display abnormalities are diagnosed based on whatthe technician knows about video processing and scanning technology. Likewise, abnormalities on plasmadisplays are generally clear pointers to a particular circuit involved in the pixel scanning. Once the concept isunderstood, troubleshooting is as easy, if not easier, than CRT symptoms. Remove the need for purity,convergence, geometry, picture sizing and centering, and you will find plasma technology is not quite so intimidating.

The sections to follow will attempt to cover different types of distortions you may encounter, along with generaltests and recommended solutions. Keep in mind that an attempt is being made to generalize up to four differentpanel design layouts but the idea is to get the technician familiar with resulting display abnormality. Detailedanalysis specific to each panel can be found in its corresponding section.

Vertical Line AbnormalitiesSince the addressing lines time the vertical plane of the pixels, attention is focused in this area of the panel drivesignals. In cases where multiple lines appear with color across the entire screen, the addressing lines are not thecause. Figure 1-4 illustrates two examples of address drivers utilizing single or multiple ICs. In both cases, theaddress information from the logic board is de-multiplexed by the drivers to control the vertical address lineswithin the panel. Notice the drivers are mounted directly to the flexible PC cable, which is part of the glass panel.They are not replaceable with conventional equipment and a failure at this point requires replacement of theentire plasma panel.

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FIGURE 1-4 - EXAMPLE OF ADDRESS DRIVERS PDP01.1-4 3/1/04

MULTIPLE DRIVE ICs SINGLE DRIVE IC

FIGURE 1-5 - SINGLE VERTICAL LINE FAILURE

ADDRESS BOARD ADDRESS BOARD

SINGLE DARK, WHITE, ORDIFFERENT COLORED LINE

SCAN DRIVER, FLEX CABLEOR PANEL.MUST REPLACE PANEL

PDP01.1-5 2/27/04

Below are some examples of the different symptoms that can appear.

Single Black, White, or Colored Vertical Line: Figure 1-5 illustrates an externally generated red raster in which asingle vertical line appears. The line may be dark, white or one of the primary pixel colors. A dark or white lineindicates a loss of drive to a single row of pixels and the type of panel used determines whether it will display aswhite or black. A colored line is caused by that particular address location being turned on continuously. Thiscan be caused by a defective drive IC, or leakage or shorts between the pads of the flexible PC connector pads.

If the panel is a single-scan design (address drivers only on the bottom), the lines usually extend from top tobottom. In a dual scan panel, the line(s) will begin at the top or bottom and end exactly at the middle of thescreen.

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FIGURE 1-6 - MULTIPLE VERTICAL LINE FAILURE

LINE MAY BE BLACK ORWHITE DEPENDING ON

PANEL DESIGN


DRIVE IC OR ADDRESSBOARD FAILURE

PDP01.1-6 2/27/04

Multiple Cluster of Black or White Lines: In Figure 1-6, an example is shown where multiple adjacent lines arenot receiving a signal. In almost all cases, the lines affected correspond directly to the number of outputs de-multiplexed by a drive IC. The problem can be a failed drive IC or loss of signal to that particular IC. A closeinspection of the drive IC at the point where the abnormality is located should be performed first. Most failuresof the drive IC will reveal signs of overheating such as cracks or burn holes. If this is found, the panel must bereplaced. If the drive IC appears intact, inspection of the flexible PC cable should be performed paying closeattention to the contact pads and the locking connector. Corrosion or foreign material could be the cause. If thecable and connector appear OK, it will be necessary to check signals at the connector. This is easily done sincethere are other drive connectors in which to compare proper voltages and signals.

TIP: Some panel designs (such as the KE50XS910) have a relay board to distribute the drive signals from thelogic board. In this case, the cables for adjacent address lines at the relay board can be swapped. If the linedefect moves to another part of the screen, the drive IC was not receiving a signal. If the line defect remains inthe same place, the drive IC is defective and the panel must be replaced.

Multiple Colored Vertical Lines: Figures 1-7 illustrates another vertical line distortion. Although this may appearto be an addressing line failure, the fact that they contain colors eliminates this possibility. Notice the distinctcutoff point at the middle of the screen. All current plasma designs used in Sony products split the horizontalscan signals between two driver boards. Although this appears to be a vertical issue, it is caused by the scancircuits, not the address circuits. Suspect a failure in the Y-SUS board. Other models refer to this circuit as ahigh voltage board.

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FIGURE 1-7 - MULTIPLE COLORED LINES PDP01.1-7 2/27/04

SCAN DRIVE BOARDSAND DRIVERS

DRIVE IC, FLEX CABLE, ORDEFECTIVE PANEL

FIGURE 1-8 - SINGLE SCAN LINE FAILURE PDP01.1-9 2/27/04

Horizontal Line AbnormalitiesIn figure 1-8, a thin line of missing video indicates a loss of signal to an individual line. This can be caused by anindividual scan line being inoperative due to an open connection to the panel or a failure of the drive IC to providethe necessary voltage to that line. Since the scan driver IC performs a de-multiplexing of the incoming signal, thefailure lies either within or after the drive IC. If the panel design uses a scan drive board in which the flexiblecable is part of the panel and driver board, or if the drive ICs are part of the flexible PC, the panel must bereplaced. In panel designs where the driver board contains connectors to the panel flex-cables, a thoroughinspection of the flexible cable connecting the panel to the driver board should be performed. If the pads on theflexible cable are OK, a check of each scan-drive output from the driver IC must be made with an oscilloscope toeliminate the panel assembly as the cause.

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FAILED IC

SCAN BOARDSAND DRIVERS

FIGURE 1-9 - MULTIPLE SCAN LINE FAILURE PDP01.1-9 2/27/04

BURN HOLE

SURFACE CRACK

FIGURE 1-10 - DAMAGED SCAN DRIVE IC PDP01.1-10 2/27/04

Figure 1-9 illustrates a failure of a large number of horizontal scan lines. Most panel designs use two separateboards for the scan drivers. The point to note is that any failure of a scan IC will prevent display of succeedinglines to the point where the board ends at the middle of the panel. The first IC that fails to light up the scan linesis the culprit. In some cases, a visual inspection of the drive ICs may reveal the failed component. Look for anysigns of scorching or burn holes as shown in figure 1-10. Scan ICs damaged due to overheating will usuallycause the self-diagnostics circuits to indicate a panel failure alarm. How this alarm is displayed varies frommodel to model and is covered in training material specific to that model.

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FIGURE 1-11 - ABNORMAL COLORS PDP01.1-11 2/27/04

FIGURE 1-12 - SCAN DRIVE DISTORTION PDP01.1-12 2/27/04

Abnormal Luminance and/or ColorIn Figure 1-11, one of any number of symptoms is shown that can be caused by a failure in the scan drivecircuitry. Background video may or may not be present. There might only be luminance component. The keysymptom to observe is the “analog” appearance of the distortion. Video signals processed before reaching thepanel will usually have a digital-appearing distortion. If the scan drive board is at fault, the distortion will tend tohave a smear to it and will appear whether a signal is input or not.

Another example of distortion caused by the scan circuits is shown in Figure 1-12. The upper or lower half of thescreen video will have distortion similar to colored snow. This symptom is deceiving and leads one to believe thelogic or scan drive board to be at fault due to the “digital” appearance. The clue here, once again, is how thedistortion occurs in exactly one half of the screen. The two boards containing the scan driver ICs should beexamined for any signs of component overheating by looking at or carefully touching any semiconductor devices.Distortions such as this can be caused by leaky components causing a load on the voltage lines or unwantedoscillations.

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Replacing a Defective PanelOnce it is determined that the plasma panel needs replacement, the proper procedures must be followed toremove it from the unit. This procedure varies from model to model. This is covered in the additional chaptersof this training manual.

Due to varying tolerances of plasma panels, certain voltage settings must be adjusted for that particular panel.Most replacement panels will come with the Logic, Address and Scan boards installed and pre-adjusted. Incases where the panel does not, a label is located on the rear of the panel indicating the proper voltages settingsunique to that panel. All panels require the proper setting of the scan (Vs) and address (Va). Other panels mayrequire one or two additional voltages to be properly adjusted. These will also be indicated on the label. Figure1-13 illustrates a typical label indicating the proper scan and address voltages. Note the two additional voltages(Vw and Vx) indicated on the label. The method for adjusting panel voltages is dependent on the panel designused. Some can be adjusted on the power supply board and others will appear on the scan boards. Certainmodels require an interface jig to change EEPROM data. Be certain to check for the latest updates regardingpanel voltage adjustments pertaining to the model you are servicing by accessing the Sony service website atHTTP://service.sel.sony.com.

PANEL TYPE PANEL SERIAL NUMBER

VOLTAGESETTINGS

FIGURE 1-13 - TYPICAL PANEL LABELSPDP01.1-13 3/23/04

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2. Troubleshooting the KE37/42XS910

Chapter 2 - Troubleshooting the KE37/42XS910

OverviewThe KE37/42XS910 is a high-definition-ready plasma television with a built-in NTSC tuner along with the necessaryvideo processing circuitry to accept composite, Y/C, component, and DVI video sources along with analog L/Raudio. Other plasma models function as monitoring devices and rely on an external receiver (known as a MediaBox) to receive and process video and audio.

This chapter will point out the circuits that are unique to this model along with a description of each board’sfunction. Practical troubleshooting methods will be discussed followed by a systematic procedure for disassemblingand re-assembling the unit. Plasma televisions rely on a large gassed-filled glass panel to generate video. It isimportant that this glass panel be properly braced and secured by brackets and the back cover assembly. Aconsiderable amount of shielding is also required due to the high voltage levels generated by the scan drivers.Because of this, a large number of screws are utilized. A full disassembly can require the removal of a hundredscrews or more!

Another factor is the use of a number of circuit boards spread throughout the rear of the large panel assembly.This requires the use of many wiring harness mounts and paths. It is extremely important to route these wires intheir correct configuration to minimize interference and prevent any wires from being pinched or cut. Clearancesbetween shields, brackets and the rear cover are minimal so this is quite important. An extensive use of illustrationswill be used to assist the technician in routing the wiring correctly and return all of the screws back to their originallocation.

Signal ProcessingOverall Block DiagramReferring to Figure 2-1, an overall block diagram demonstrates the various paths for the different video andaudio inputs. A NTSC tuner is located on the A board. A/V inputs 1, 2 and 3 accept composite or Y/C video alongwith L/R audio. A/V inputs 4 and 5 accept component video only, along with L/R audio. Video resolutions of 480i,480p, 1080i and 720p are supported.

The DVI input receives differential RGB digital video information along with analog L/R audio. The UD boardcontains the receiver/decoder to convert the digital signal to Y/CB/CR along with HDCP control.

The HM board contains a Memory Stick™ slot for display of JPEG still pictures and MPEG1 audio/video playback.The information from the memory stick is processed and sent via a LVDS (Low Voltage Differential Signal)transmitter to the MS2F board. The video and/or audio signals are processed and D/A converted. Audio is sentto A/V switch2 while video information is sent to the DIC2 board.

NOTE: The MS2F board is enclosed within a shielded assembly (known as the DM Block) containing the DIC2and DE2 boards. Although the service manual refers to this as a replaceable assembly, it is not. The boardsinside must be replaced individually.

All non-component video signals and analog L/R audio are controlled by AVSW1 and AVSW2. Component andDVI video are routed through a component interface and applied to a video switch. This video switch allows theselection of DVI, component, Y/C or composite video signals to be routed to the main video process path. Thesub-video path can only accept signals from the tuner and inputs 1 through 3 and is, therefore, limited to 480iresolutions only. The main and sub video are routed to the DIC2 (Digital Imaging Core) board.Necessary standby and switched voltages are generated by the regulator block (sometimes referred to as PSU).Analog audio is received by the K board where it is amplified to drive a set of speakers.

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FIGURE 2-1 - KE37/42XS910 SERIES OVERALL BLOCK

ANTIN

INPUT 1

INPUT 2

INPUT 3

INPUT 4

DVIINPUT

MEMORYSTICKINPUT

REGULATORBLOCK

NTSC TUNER

AVSW1H2

BOARD

COMPI/FINPUT 5

UDBOARD

MS2FBOARD

VIDEOSW

MAIN V

A BOARD

AUDIOPROCESS

AVSW1SUB V

AUDIO

HMBOARD

CCP2MAIN

DIC2 BOARD

CCP2MAIN

MID

DRC

MIDUC

DCPPANELDRIVER

DE2 BOARD

TVMICRO

PANELMICRO

K BOARD

AUDIOAMP

TOPANEL

TOSPEAKERS

LR

PDP01.2-1 3/23/04

Video Signal ProcessingReferring to Figure 2-2, the main, sub and memory stick paths are shown entering the DIC2 board. Main videois processed by CCP2 (Composite to Component Processor) if it is component. If the main video signal is 480i,the DRC performs the necessary line doubling to 960i. The sub video path only receives composite or Y/Csources. It is, therefore, impossible to display a side-by-side twin view of two signals higher than 480i resolution.480p resolutions and above can only be processed by the main path and the picture will always be on the left sidewhen Twin View™ is selected.

All video signals above 480i are processed by MID and D/A converted to 16bit component (8bit Y and 8bit CB/CR). The digital component signal is sent via a LVDS transmitter to the DE2 board.

The DE2 board serves as an interface between the video processing circuits and display panel. DCP (DigitalComponent Processor) performs the necessary scaling of the video signal to conform to the native resolution ofthe panel. The scaled video is sent to the panel driver as 4:2:2 and is processed to 4:4:4 10bit RGB where thelogic board (not shown) allocates the video information to its corresponding pixels.

Note that the DE2 board contains two micro-controllers. One controls the television functions and user interfacewhile the other controls the panel driver. The TV micro-controller generates menu and service OSD. Keep thisin mind as it becomes an important tool in troubleshooting video problems when trying to isolate the DIC2 andDEC2 boards as the cause. A NVM IC contains the customer preference settings along with service setup data.The NVM IC connected to the panel micro-controller contains necessary information for the panel such as whitebalance and gamma settings.

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FIGURE 2-2 - KE37/42XS910 SERIES VIDEO PROCESSING

MAIN VIDEO

CV/YC/YUVLPF

MID

CCP2MAIN

DRC

LPFCCP2SUB

SUB VIDEO

CV/YC

DIC2 BOARD

LVDSTX

FROMA BOARD

DE 2 BOARD

DE 3 BOARD

(KE37/42SX910)

(KE50SX910)

DCPPANEL

DRIVERLVDS

TX

PANELMICRO

CTL SIG OUTCTL SIG INI2C BUS

LVDSRX

NVM NVM

SIRCSI2CBUS

TVMICRO

OSD LOCAL BUS

IC4408 IC4001

TOPLASMAPANEL

PDP01.2-2 3/23/04

MS VIDEO

The Plasma PanelFigure 2-3 shows a layout of the plasma panel and associated circuit boards necessary to control the pixels. TheY-SUS and X-SUS boards generate the necessary pulses to sustain each horizontal line of pixels so that theaddress lines controlled by the ABUSL and ABUSR boards can light each vertical row of pixels. The scan andaddress line timing is controlled by the logic board.Notice the use of eight drive ICs from the Y-SUS board to the panel. The Y-drive signal utilizes the most energyto sustain the pixel lighting. This circuit consumes the most power and is a likely suspect when a failure occurscausing a completely dead panel display. These drivers should always be inspected when the panel does notlight, especially if a panel failure warning appears from the diagnostics circuits. They are also part of the flexiblecable molded into the panel, so the entire panel must be replaced. A new panel assembly is supplied with thelogic, scan and address boards installed, thereby eliminating the need for most panel alignments (especiallygamma).The logic board receives RBG digital data at CN1 from the DE2 board (not shown). Data from the DE2 isreceived via LVDS transmission and converted back to 30-bit parallel RGB to be allocated to each necessarypixel in accordance with scan and address timing. The logic board also contains NVM data for voltage settingsunique to the panel installed in the unit. If the logic board is replaced to complete a repair, the NVM IC can bephysically swapped to transfer these settings for the existing panel. It is an eight-pin surface mounted IC designatedas M19 on this model.

The necessary voltages for the audio, video and panel drive circuits are generated by the PSU board. Powercontrol is achieved via a logic high command from the DE2 board. The logic board sends several control lines tothe PSU board to turn on certain voltages for the Y and X-SUS boards. Voltage and current protection ismonitored by several circuits.

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FIGURE 2-3 - KE37/42XS910 PANEL AND DRIVERS

CN51

FROMDE2BOARD

RGB INPUT (LVDS)

Y-SUSBOARD

CN31

PLASMA PANEL

ADM1 ADM2 ADM3 ADM4 ADM5 ADM6 ADM7 ADM8

ABUSLBOARD

ABUSRBOARD

XBB

XBB

CN21

CN41

CN4CN6

CN3 CN2

CN1

PDP01.2-3 3/23/04

FPC ANDSCAN ICs

FPC FPC FPC FPC FPC FPCFPC FPC

FPC

FPC

LOGICBOARD

POWER SUPPLYACIN

PSUBOARD

TO A, DIC2, DE2BOARDS

TO PANELBOARDSPOWER CTL

X-SUSBOARD

Protect and Self-DiagnosticsThe power/standby LED will indicate certain faults detected by the protection monitoring circuits to assist indiagnosing where a potential failure may be located. Any of the five fault indications will result in a unit that willnot power up or may power up and then shut down. The LED will blink in 0.5-second intervals followed by a threesecond separation period. They are as follows:

Four blinks: One or more of the cooling fan motors is not functioning. Fan rotation feedback lines for each fanare monitored. If one fan is not rotating, check for B+ to that fan. If present, replace the fan. If B+ is present, orif all fans are not rotating, replace the A board.

Six Blinks: This indicates a B+ power error. The switched 5V line on the power supply board is not present. Ifthe power control line (VCEGO) at CN7 pin 8 is going high, replace the PSU board. If not, the DE2 board may beat fault.

Seven Blinks: A DC voltage has been detected on one or more of the speaker lines. Replace the K board.Eight Blinks: An over-voltage condition has been detected at the DC-DC converter located on the X-SUS board.Replace the board.

Nine Blinks: A panel module or over-temperature failure has been detected. There are two thermistors locatedon the panel. One detects the temperature of the large heat sink on the Y-SUS board and the other, the overalltemperature of the panel assembly. Over-current is also detected for the scan drive circuits. If the LED blinks

17


panel alarm when first turned on, the panel monitoring circuits have detected a fault. This fault can be caused bya loss of the scan or address voltages. An over-current condition on these lines will also trigger a panel alarm.This is usually caused by a shorted scan-drive IC. Signs of overheating, such as cracks and/or blistering, usuallyoccur on the IC surface. Over-temperature conditions will usually occur if the unit has been running for a while.This can be caused by excessive ambient room temperatures or improper installation of the display device.

TroubleshootingOverviewDue to the large amount of digital processing, along with scan and address methods used, plasma televisionscan generate symptoms that are unfamiliar to most technicians. The following troubleshooting techniques shouldhelp to isolate the cause in most cases. Documentation of unusual symptoms or known failures will be keptupdated on the ESI server. Check the service website at HTTP://service.sel.sony.com for the latest bulletinsregarding the model you are servicing.

Circuit failures in a plasma television generally fall into three categories:

1. Dead set

2. Protection events

3. No or distorted video

Units that exhibit no signs of operation require a few checks be done to determine if the power supply is at fault.The DE2 board contains the television micro-controller that is responsible for turning on certain switched voltageson the power regulator board along with telling the panel circuits to begin operating.Protect shutdown events are identified by the number of times the timer LED blinks. Most protect events arecaused by excessive current on a voltage line or the loss of a certain voltage.A no video condition requires elimination of the plasma panel and its associated drive circuits before analyzingthe video process circuits. The most important item to remember when servicing plasma displays is: If anylighting of the pixels is seen, the panel, along with the scan and address boards, is OK. It also indicatesthe presence of the required voltages for these circuits.Video distortions are easily isolated between the process circuits and panel/drive circuits by how they appear onthe screen. Panel failures will usually display a fixed distortion or missing video on a horizontal or vertical axis.Video process circuit failures tend to be more random and usually across the entire screen.Since all repairs are board level, each scenario above will be approached using flowchart diagrams to properlyisolate the failure to a particular board.

Troubleshooting a No Power ConditionIf a set fails to turn on or appears “dead” the first item to check is whether the power supply is operational. ThePSU board has a standby section generating a 3.3V and 5V source. If these are operating, the unit is not “dead”.The flowchart in Figure 2-4 is an initial starting point to determine this. If the standby circuit is operational, thenext step is to determine if the power supply is at fault or is not being told to turn on. There are other voltagesturned on by the Logic board. The symptom will usually be no picture with audio and the pixels on the panel arenot priming. Using the flowchart in Figure 2-5 should lead you in the right direction.

18


FIGURE 2-4 - KE37/42XS910 DEAD SET PRELIMINARY CHECK

Unit will not turn on

STBY LED lit orblinking?

No

Replace PSU board

Yes

Continuousblinking orgroups?

Go to protectdiagnostics chart

Fig 2-6

Groups

Does panel light?

STBY 3.3V atCN9002 pins 1~4?

No

Replace DE2 board

Continuous

Yes

PSU board probablyOK. Go to videoTroubleshooting

No Go to power supplytroubleshooting chart

Fig 2-5

PDP01.2-4 3/23/04

Yes

19


FIGURE 2-5 - KE37/42XS910 POWER SUPPLY TROUBLESHOOTING

Power Supply Troubleshooting(Standby OK)

High at CN7pin 8 on PSU

board?

No

Replace Logic board

Yes

VCC 5V atCN23 pin 3PSU board?

5V reg failureReplace PSU board

High at CN7pin 6 on PSU

board?

High atCN3301 pin 5 on

DE2 board?

Yes

Replace DE2 board

Yes

NoReplace Logic board

No

No

Yes

63VDC (VA) atCN23 pin 1 onPSU board?

No

High atCN7 pin 12 onPSU board?

85VDC (VA) atCN23 pin 9 onPSU board?

Replace Logic boardNo

Yes

Replace PSU board

High atCN7 pin 14 onPSU board?

Yes

NoReplace Logic board

No

Replace Logic board

Yes

Replace PSU board

PDP01.2-5 4/16/04

20


FIGURE 2-6 - KE37/42XS910 DIAGNOSTICS TROUBLESHOOTING

Self-diagnostics indication

Four blinks ofSTBY/PWR LED?

No

Check connections tofan. Replace fan if

OK

Yes

Six blinks?

More than one fannot rotating?

YesCheck for 14VDC at

CN9002 pin 10 of PSUboard. Replace PSU ifnot present. Replace A

board if present

Replace PSU board

No

No

Yes

Seven blinks?

No

Eight blinks?

Replace K boardYes

5VDC atCN9002 pin 9PSU board?

No

Yes

Replace DE2 board

Replace X-SUSboard

Yes

PDP01.2-6 4/16/04

Nine blinks?Yes

Go to "No Video"troubleshooting

flowchart Figure 2-7

Self-Diagnostics TroubleshootingFigure 2-6 shows a flowchart to aid in locating the cause of self-diagnostics indications displayed by the standby/power LED. A history of any diagnostics events can be viewed by pressing “Display”, “5”, “Volume –”, and the“Power” buttons, in order, on the remote commander when the unit is off.

21


Video Circuit TroubleshootingVideo circuit failures manifest themselves in two different ways: No video at all or abnormalities in the picturedisplay. In cases where no video is displayed, it is crucial to determine if the plasma panel is able to “prime”.Priming involves the generation of scan signals on the horizontal address lines to light the pixels just to the pointwhere they emit a small amount of light. Once this is accomplished, the address lines complete the necessary“firing” of each pixel to generate the appropriate level of each pixel color to reproduce and image. If the panel ispriming, it is a good indication that everything is OK with the glass panel and associated drive circuits. Focus willnow turn to the video process circuits.

If the panel is not priming and there is audio, a check of the required voltages is necessary to eliminate powersupply line failures as the cause. Use the flowchart in Figure 2-5 to determine if this is the cause. If the powersupply voltages appear OK, there may be a failure of the Y-SUS or X-SUS board. Only these boards arerequired to function to prime the panel. If the panel has been compromised and there are no visible signs ofcracks, the only way to determine this is to check for scan pulses exiting the Y-SUS board. These pulses arequite large (170 to 230VPP). If present, it indicates the panel has lost its inert gas.

A panel alarm may also be indicated by the standby/power LED. It will be flashing in sequences of nine. This isusually caused by an over-current condition and the likely suspect is a shorted scan drive IC. These driversusually exhibit signs of overheating damage with burn holes and cracks appearing on their surface. The paneldesign used in this model incorporates the drivers on the flexible cable, which is part of the glass panel.Replacement of the panel is required if this occurs.

Figure 2-7 is a flowchart that is helpful as a starting point for a “no video” condition with functional audio. If audiocannot be heard, it is best to return to the power supply troubleshooting flowcharts. If the problem is determinedto be in the video process circuits, the A, DIC2 and DE2 boards must be isolated as the cause. The flowchart inFigure 2-8 will provide assistance.

NOTE: The DIC2 and DE2 boards are enclosed within a shielded assembly known as the DM block. In order toaccess these boards for removal, the shield assembly must be taken apart. There is a LVDS cable connectingthe two boards and this cable is looped outside of the shields. It is protected by a plastic cover. It is veryimportant to remove this plastic cover and unplug both ends of the LVDS cable before attempting to separate theboards from the housing. Failure to do so will cause the shield to snag the LVDS connectors and damage them.The connectors are easily removed by pinching the release tabs and pulling them out. This is shown in Figure 2-9

22


No Video

Signs ofoverheating onany scan-drive

ICs?

Yes

No

Replace panel assembly

VS (85VDC)CN23-8 on PSU

board?

Go to power supplytroubleshooting flowchart

Figure 2-5

No

VS (85VDC)CN23-8 on PSU

board?

Yes

Go to power supplytroubleshooting flowchart

Figure 2-5

No

Is panel Priming?* Go to flowchart Figure 2-8Yes

No

*Panel priming is determined byobserving the screen for signs ofpixel lighting. It is a dark raster

similar to reference black in CRTunits. It is best detected by turning

the unit on and off to distinguish thedifference between "true black"

(panel off) and reference black (panellit).

FIGURE 2-7 - KE37/42XS910 INITAL "NO VIDEO" CHECK PDP01.2-7 4/20/04

Yes

Check for 85VPP scanpulses on connectorsbetween Y-SUS board

and scan drive ICs.Replace Y-SUS if none

present. Replace Panel ifpulses present.

23


FIGURE 2-8 - KE37/42XS910 VIDEO PROCESS TROUBLESHOOTING

No videoPanel is primed, audio OK

Can OSD bedisplayed?

No

Re-seat connector

Yes

Picture on rightside when TwinView engaged?

Replace DIC2 board

LVDS connectorfrom DE2 to Logicboard connected?

Yes

Replace DE2 boardNo

No

Yes

No

No

Does componentvideo input display

picture?Replace DIC2 boardYes

Can picture fromMemory Stick be

displayed?

Yes Replace A board

Replace DIC2 board

PDP01.2-8 3/2/04

24


FIGURE 2-9 - DM BLOCK LVDS CONNECTORS PDP01.2-9 3/4/04

DM BLOCK

REMOVEPLASTIC COVER

LVDSCONNECTORS

Troubleshooting Display Panel AbnormalitiesSymptoms appearing on the screen during panel and drive circuit failures are generally easy to identify. Sincethe panel is controlled by intersecting scan and address lines, distortions, abnormal colors or missing pixel datawill manifest themselves as horizontal or vertical lines or may occur in entire blocks. If you have acquired thisonly this chapter for troubleshooting the KE37/42XS910 model, obtain the section in Chapter 1, which containsadditional information applying to general plasma theory and troubleshooting.

In Figure 2-10, some examples of address circuit failures are shown. If one or more vertical lines of videoinformation are missing or filled with a solid color, the panel will likely have to be replaced. Address informationis sent to the right and left address boards (ABUSL and ABUSR). Each board processes the RBG digital data,which is then sent to each ADM processor. The ADM processors send ten lines of multiplexed data to theFlexible PC connectors. Each FPC contains three drive ICs where the signals are de-multiplexed to 57 lineseach for the address lines on the panel.

Single line failures are caused by problems in the drive outputs. Since the drivers are mounted to the FPCassembly, the panel must be replaced. Multiple lines of missing video, creating a block of no information, can becaused by the logic or address boards. It is unlikely that three drive ICs have failed. Suspect the address boardfirst, followed by the logic board.

Figure 2-11 illustrates potential symptoms that might be seen if a failure occurs in the scan drive circuits. Thescan drive ICs are mounted to flexible PC cables so any single missing lines of video will require a panelreplacement. If one-half of the picture is missing information, examine the drive ICs on the FPC adjacent to thefailure for signs of overheating to determine whether the panel or Y-SUS board should be replaced.

25


FIGURE 2-10 - KE37/42XS910 PANEL ADDRESS FAILURES

Y-SUSBOARD


ABUSLBOARD

ABUSRBOARD

XBB

XBB

FPC ANDSCAN ICs


FPC

FPC

LOGICBOARD

BLANK OR DIFFERENTCOLORED LINE

MULTIPLE MISSING LINES

PDP01.2-10 3/23/04

X-SUSBOARD

FIGURE 2-11 - KE37/42XS910 PANEL SCAN FAILURES

Y-SUSBOARD


ABUSLBOARD

ABUSRBOARD

XBB

XBB

FPC ANDSCAN ICs


FPC

FPC

LOGICBOARD

ONE-HALF SCREEN MISSINGSINGLE MISSING SCAN LINES

PDP01.2-11 3/23/04

X-SUSBOARD

26


FINGER HOLES FOR REMOVAL

FIGURE 2-12 - SPEAKER COVER REMOVAL PDP01.2-12 3/4/04

DisassemblyOverviewThis section will cover the required steps to disassemble the unit down to panel replacement. Due to the largenumber of screws involved, be sure to have a container to place them in during the procedure. It is extremelyimportant to place the plasma television on a repair stand of adequate size along with a piece of foam padding toprotect the screen. Be certain the padding is at least ¾ of the screen size to prevent flexing of the glass panel,which is easily damaged. The glass can withstand moderate bending but the barrier ribs separating the verticallines of pixels are easily damaged by minor flexing.

HINT: Most of the screws securing shields and circuit boards are 3mm machine with attached flat washers.Larger machine and self-tapping screws are allocated to support brackets and the rear cover.

Speaker Housing and Rear Cover RemovalAs shown in figure 2-12, remove the left and right rear speaker covers by pulling upward, using the finger accessholes. This exposes the rear cover screws on each side. Remove the following screws for the rear cover:

• Four 5X25 machine (black) securing the stand. The stand must be removed first.

• Fourteen 4X16 black, self tap (black)

• Sixteen 3X6 machine (black)

• Six 4X10 machine (black)• Six 5X10 machine (black)

27


Y-SUS BOARD PSU BOARD X-SUS BOARD

A BOARD(UNDER SHIELD)

DM BLOCK(DIC2, DE2, MS2A)

K BOARD

FIGURE 2-13 - KE37/42XS910 BOARD LAYOUT PDP01.2-13 3/23/04

FIGURE 2-14 - SPEAKER HOUSING REMOVALPDP01.2-14 3/2/04

REMOVE 9 SCREWS(4x12 SELF TAP)

Once the rear cover has been removed, the view shown in figure 2-13 is seen. The Y-SUS, X-SUS, Logic, ScanDrive and Address boards are not visible as they are located under the shields. Use this view as a guide whenre-assembling the unit to properly dress the cable harnesses.Removal of the left and right speaker housing is shown in Figure 2-14. This step is not necessary if the plasmapanel is to be replaced.

28


REMOVE FOUR 6x12SELF-TAP SCREWS AND

GROUND WIRE

REMOVE TWO 3X6 MACHINESCREWS AND NYLON LOCK

PINS

FIGURE 2-15 - VIDEO INPUT COVER AND SHIELD REMOVAL PDP01.2-15 3/4/04

REMOVE NUTSSECURING DVICONNECTOR

A Board and DM Block RemovalFigure 2-15 illustrates the location of the video input and processing circuit boards. The cover over the videoinput jacks must be removed. This cover also secures the AC input receptacle. The earth ground wire must alsobe removed as shown. The metal shield above the input connectors covers the A board. Use caution whenremoving the nylon lock nuts as it is easy for them to fall out when lifting the shield.The DM block must be removed after the video input cover and A board shield since it attaches to the A boardwith a large connector (CN8001). Remove two connectors CN1813 and CN1814 (not shown) at the bottom ofthe DM block. Loosen the four machine screws securing the DM block and GENTLEY lift it from the A board.

There is a LVDS connector located on the upper part of the DM block connected to the Logic board. LVDScables use thin wires. They are easily damaged. Remove the two LVDS and one communication connector asshown in Figure 2-16.

29


MEMORY STICK LVDSCONNECTOR

DE2 TO LOGICBOARD LVDSCONNECTOR

COM CONNECTOR

FIGURE 2-16 - DM BLOCK REMOVAL PDP01.2-16 3/4/04

CN8003

CN8002

CN8005

CN8601

CN8230

FIGURE 2-17 - A BOARD REMOVAL PDP01.2-17 3/4/04

CN8001

In Figure 2-17, removal of the A board is shown. The listed connectors are removed along with the RF inputcable to the tuner. Four 3X6 machine screws secure the board. Remove the board and place in a safe location.

30


CN3062

CN3061 CN3001

GROUNDCONNECTORS

FIGURE 2-18 - K BOARD REMOVAL

UNPLUG ALL CABLECONNECTORS

PDP01.2-18 3/4/04

K Board RemovalIn Figure 2-18, removal of the K board is shown. The board has a shield on top that has been removed. Theshield is secured with two 3X6 machine screws. The bottom shield securing the K board is attached to thechassis with four 3X6 machine screws. Remove the three cable and two ground connectors as shown. Removethe cables from the purse-lock retainers. Unplug all connectors attaching cables to cables. Set cable harness tothe right side and out of the way. Note the layout of the cables in this picture. It will be useful when re-assemblingthe unit.

Power Supply RemovalFigure 2-19 shows the power supply (PSU) board after the fan bracket (not shown) has been removed. Theboard is secured by seven 3X6 machine screws. If the board is going to be removed for replacement of thepanel, only CN6, CN7 and CN23 need to be removed. The remaining connectors are for the K and DM block.Simply place the DM block on top of the PSU board and remove the assembly with the K board and fan cablesas shown in Figure 2-20.

31


CN23

CN7CN6

FIGURE 2-19 - POWER SUPPLY REMOVAL PDP01.2-19 3/4/04

FIGURE 2-20 - DM AND PSU REMOVAL PDP01.2-20 3/4/04

32


REMOVE FOUR 3X6MACHINE SCREWS

LOOSEN SELF-TAPPING SCREWS

FIGURE 2-21 - LOWER SHIELD REMOVAL PDP01.2-21 3/23/04

Lower Shield RemovalIf the panel is going to be replaced, the lower shield assembly that held the A board and DM block must beremoved. Figure 2-21 illustrates this. It is secured by four 3x6 machine and two 3X12 self-tapping screws. Theself-tapping screws only need to be loosened.

Y-SUS and X-SUS Shield RemovalFigure 2-22 shows the Y-SUS board shield and its removal procedure. This shield must be removed to accessthe Y-driver boards and ICs for inspection and/or replacement. This photo shows the K board installed. Unlessthe K board needs replacement, it can be left intact. Two 3X6 machine and four 3X12 self-tap screws aresecuring the unit. Pay close attention to the self-tap screw located below the fan motor. Unplug the fan motorand remove the shield.Figure 2-23 demonstrates the removal of the X-SUS shield. Note the layout or the wiring in the purse-lockretainers and the removal of ground connections for reference when re-installing the shield.

33


FIGURE 2-22 - Y-SUS SHIELD REMOVAL

REMOVE TWO3x6 MACHINE

SCREWS

REMOVE FOUR4x12 SELF-TAP

SCREWS

UNPLUGFAN CABLE

PDP01.2-22 3/4/04

FIGURE 2-23 - X-SUS SHIELD REMOVAL PDP01.2-23 3/4/04

REMOVE TWO 3x6MACHINE SCREWS

REMOVE ONE 3x6MACHINE SCREW AND

GROUND CABLE

REMOVE FOUR 3x6SELF-TAP SCREWS

UNPLUG FAN

UNPLUG SPEAKERCONNECTORS AND

GROUND LUGS

34


REMOVE FOUR 4x16SELF-TAP SCREWS AT

BOTTOM

REMOVE FOUR 4x8MACHINE SCREWS AT

TOP

LOGIC BOARD

ADDRESSBOARDS

FIGURE 2-24 - PANEL BRACKET REMOVAL PDP01.2-24 3/4/04

Panel RemovalOnce all of the above circuit boards and shields have been removed, the panel is ready for removal. Two largebrackets are attached to the panel with four 5X10 machine screws. Although the brackets do not come with thepanel, they should be left intact to ease the removal. The replacement panel will come with disposable bracketsto assist in installation. The original brackets can then be transferred to the new panel.By removing the four 4X8 machine and four 4X12 self-tap screws securing the bracket to the top and bottom ofthe filter glass assembly, the panel can be lifted out. This is illustrated in Figures 2-24 and 2-25. Notice thelocation of the Logic and Address boards in Figure 2-24.NOTE: Panel replacement should only be performed in the shop. The removal of a large number of self-tapscrews creates a considerable amount of plastic contaminants. Accumulated dust, along with the plastic pieces,can easily fall onto the backside of the filter glass. This must be thoroughly removed using air from a compressor.It is extremely important to remove all contaminants before installing the new panel.The replacement panel will come with the Logic, Address, Y-SUS and X-SUS boards installed. The serial numberof the panel will need to be documented if it is replaced. The label containing the serial number is visible abovethe Y-SUS board after the shield has been removed as outlined in Figure 2-22. A view of the label will be shownnext in the Y-SUS board removal.

35


FIGURE 2-25 - KE37/42XS910 PANEL REMOVAL PDP01.2-25 3/23/04

REMOVE NINE SILVER3x6 MACHINE

SCREWS

FIGURE 2-26 - Y-SUS BOARD REMOVAL PDP01.2-26 3/23/04

Y-SUS and X-SUS Board RemovalShould the need arise to replace the Y-SUS or X-SUS boards, removal is illustrated in Figure 2-26 for the Y-SUSboard and Figure 2-27 for the X-SUS board. Note Figure 2-27 and the location of the panel serial number andvoltage adjustment labels. Also note the Y-Scan drive ICs located on the large flexible PC cables attached to theplasma panel in Figure 2-26.Both boards require the removal of nine screws each in order to properly unplug the large connectors. Themounting holes on the boards sit on top of a post with a shank that prevents horizontal movement of the boardsunless lifted slightly.

36


REMOVE NINE 3X6 MACHINESCREWS

FIGURE 2-27 - X-SUS BOARD REMOVAL PDP01.2-27 3/23/04

LABELS FOR PANELID AND VOLTAGE

SETTINGS

37

3. Troubleshooting the KE50XS910

Chapter 3 - Troubleshooting the KE50XS910OverviewThe KE50XS910 is a high-definition-ready plasma television with a built-in NTSC tuner along with the necessaryvideo processing circuitry to accept composite, Y/C, component and DVI video sources along with analog L/Raudio. Other plasma models function as monitoring devices and rely on an external receiver (known as a MediaBox) to receive and process video and audio.

This chapter will point out the circuits that are unique to this model along with a description of each board’sfunction. Practical troubleshooting methods will be discussed followed by a systematic procedure for disassemblingand re-assembling the unit. Plasma televisions rely on a large, gassed-filled glass panel to generate video. It isimportant that this glass panel be properly braced and secured by brackets and the back cover assembly. Aconsiderable amount of shielding is also required due to the high voltage levels generated by the scan drivers.Because of this, a large number of screws are utilized. A full disassembly can require the removal of a hundredscrews or more!Another factor is the use of a number of circuit boards spread throughout the rear of the large panel assembly.This requires the use of many wiring harness mounts and paths. It is extremely important to route these wires intheir correct configuration to minimize interference and prevent any wires from being pinched or cut. Clearancesbetween shields, brackets and the rear cover are minimal so this is very important. An extensive number ofillustrations will be used to assist the technician in routing the wiring correctly and returning all of the screws backto their original location.

Signal ProcessingOverall Block DiagramReferring to Figure 3-1, an overall block diagram demonstrates the various paths for the different video andaudio inputs. A NTSC tuner is located on the A board. A/V inputs 1, 2 and 3 accept composite or Y/C video alongwith L/R audio. A/V inputs 4 and 5 accept component video only along with L/R audio. Video resolutions of 480i,480p, 1080i and 720p are supported.

The DVI input receives differential RGB digital video information along with analog L/R audio. The UD boardcontains the receiver/decoder to convert the digital signal to Y/CB/CR along with HDCP control.

The HM board contains a Memory Stick™ slot for display of JPEG still pictures and MPEG1 audio/video playback.The information from the memory stick is processed and sent via a LVDS (Low Voltage Differential Signal)transmitter to the MS2F board. The video and/or audio signals are processed and D/A converted. Audio is sentto A/V switch2 while video information is sent to the DIC2 board.

NOTE: The MS2F board is enclosed within a shielded assembly (known as the DM Block) containing the DIC2and DE3 boards. Although the service manual refers to this as a replaceable assembly, it is not. The boardsinside must be replaced individually.

All non-component video signals and analog L/R audio are controlled by AVSW1 and AVSW2. Component andDVI video are routed through a component interface and applied to a video switch. This video switch allows theselection of DVI, component, Y/C or composite video signals to be routed to the main video process path. Thesub-video path can only accept signals from the tuner and inputs 1 through 3 and is, therefore, limited to 480iresolutions only. The main and sub video are routed to the DIC2 (Digital Imaging Core) board.

Necessary standby and switched voltages are generated by the regulator block (sometimes referred to as PSU).Analog audio is received by the K board where it is amplified to drive a set of speakers.

38


FIGURE 3-1 - KE50XS910 SERIES OVERALL BLOCK

ANTIN

INPUT 1

INPUT 2

INPUT 3

INPUT 4

DVIINPUT

MEMORYSTICKINPUT

REGULATORBLOCK

NTSC TUNER

AVSW1H2

BOARD

COMPI/FINPUT 5

UDBOARD

MS2FBOARD

VIDEOSW

MAIN V

A BOARD

AUDIOPROCESS

AVSW1SUB V

AUDIO

HMBOARD

CCP2MAIN

DIC2 BOARD

CCP2MAIN

MIDDRC

MIDMICRO

DCP PANELDRIVER

TVMICRO

PANELMICRO

K BOARD

AUDIOAMP

TOPANEL

TOSPEAKERS

LR

DE3 BOARD

PDP01.3-1 4/16/04

Video Signal ProcessingReferring to Figure 3-2, the main, sub and memory stick paths are shown entering the DIC2 board. Main videois processed by CCP2 (Composite to Component Processor) if it is component. If the main video signal is 480i,the DRC performs the necessary line doubling to 960i. The sub video path only receives composite or Y/Csources. It is, therefore, impossible to display a side-by-side twin view of two signals higher than 480i resolution.480p resolutions and above can only be processed by the main path and the picture will always be on the left sidewhen Twin View™ is selected.

All video signals above 480i are processed by MID and D/A and converted to 16bit component (8bit Y and 8bitCB/CR). The digital component signal is sent via a LVDS transmitter to the DE3 board.

The DE3 board serves as an interface between the video processing circuits and display panel. DCP (DigitalComponent Processor) performs the necessary scaling of the video signal to conform to the native resolution ofthe panel. The scaled video is sent to the panel driver as 4:2:2 and is processed to 4:4:4 10bit RGB where theDigital Video board (not shown) allocates the video information to its corresponding pixels.

Note that the DE3 board contains two micro-controllers. One controls the television functions and user interfacewhile the other controls the panel driver. The TV micro-controller generates menu and service OSD. Keep thisin mind as it becomes an important tool in troubleshooting video problems when trying to isolate the DIC2 andDE3 boards as the cause. A NVM IC contains the customer preference settings along with service setup data.The NVM IC connected to the panel micro-controller contains necessary information for the panel such as whitebalance and gamma settings.

39


FIGURE 3-2 - KE50XS910 SERIES VIDEO PROCESSING

MAIN VIDEO

CV/YC/YUVLPF

MID

CCP2MAIN

DRC

LPFCCP2SUB

SUB VIDEO

CV/YC

DIC2 BOARD

LVDSTX

FROMA BOARD

DE 3 BOARD

DCPPANEL

DRIVERLVDS

TX

PANELMICRO

CTL SIG OUTCTL SIG INI2C BUS

LVDSRX

NVM NVM

SIRCSI2CBUS

TVMICRO

OSD LOCAL BUS

IC4408 IC4001

TOPLASMAPANEL

PDP01.3-2 4/16/04

The Plasma PanelFigure 3-3 shows a layout of the plasma panel and associated circuit boards necessary to control the pixels. 30-bit RGB data is received by the interface board and processed for timing by the scan and address circuits. TheDigital Video board distributes the properly timed information.The Y-SUS and X-SUS boards generate the necessary pulses to sustain each horizontal line of pixels so that theaddress lines, which are controlled by the left and right address boards, can light each vertical row of pixels. Thescan and address line timing is controlled by the digital video board.Notice the use of 12 drive ICs from the Y-SUS board to the panel. The Y-drive signal utilizes the most energy tosustain the pixel lighting. Consequently, this circuit consumes the most power and is a likely suspect when afailure occurs causing a completely dead panel display. These drivers should always be inspected when thepanel does not light, especially if a panel failure warning appears from the diagnostics circuits. They are mountedon a two circuit boards and the flexible PC cables between the panel and the boards are permanently attached,requiring an entire panel replacement if there is a failure.The Interface board receives RBG digital data from the DE3 board (not shown). Data from the DE3 is receivedvia LVDS transmission and converted back to 30-bit parallel RGB to be allocated to each necessary pixel inaccordance with scan and address timing. The Interface board also contains NVM data for the voltage settingsspecific to the panel installed in the unit. If the Interface board is replaced to complete a repair, the NVM IC canbe physically swapped to transfer these settings for the existing panel.

The necessary voltages for the audio, video and panel drive circuits are generated by the Regulator board.Power control is achieved via a logic high command from the DE3 board.

40




PLASMA PANELXSUS

BOARD

DIGITAL VIDEOBOARD

YSUSBOARD

INTERFACEBOARD

SCAN DRIVERBOARDS

LVDS FROMDE3 BOARD

FPC

FPC

FPC

FPC

REGULATORBOARD

AC INPUT

FIGURE 3-3 - KE50XS90 PANEL AND DRIVE BOARDS PDP01.3-3

CONTROLTO PANELBOARDS

3/23/04

Protect and Self-DiagnosticsThe power/standby LED will indicate certain faults detected by the protection monitoring circuits to assist indiagnosing where a potential failure may be located. Any of the five fault indications will result in a unit that willnot power up or, may power up and then shut down. The LED will blink in 0.5-second intervals, followed by athree second separation period. They are as follows:

Four blinks: One or more of the cooling fan motors is not functioning. Fan rotation feedback lines for each fanare monitored. If one fan is not rotating, check for B+ to that fan. If present, replace the fan. If B+ is present orif all fans are not rotating, replace the A board.

Six Blinks: This indicates a B+ power error. The switched 5V line on the power supply board is not present. Ifthe power control line (VCEGO) at CN7 pin 8 is going high, replace the PSU board. If not, the DE3 board may beat fault.

Seven Blinks: A DC voltage has been detected on one or more of the speaker lines. Replace the K board.Eight Blinks: An over-voltage condition has been detected at the DC-DC converter located on the X-SUS board.Replace the board.

Nine Blinks: A panel module or over-temperature failure has been detected. There are two thermistors locatedon the panel. One detects the temperature of the large heat sink on the Y-SUS board and the other the overalltemperature of the panel assembly. Over-current is also detected for the scan drive circuits. If the LED blinks a

41


panel alarm when first turned on, the panel monitoring circuits have detected a fault. This fault can be caused bya loss of the scan or address voltages. An over-current condition on these lines will also trigger a panel alarm.This is usually caused by a shorted scan-drive IC. Signs of overheating, such as cracks and/or blistering, usuallyappear on the IC surface. Over-temperature conditions will usually occur if the unit has been running for a while.This can be caused by excessive ambient room temperatures or improper installation of the display device.

TroubleshootingOverviewDue to the large amount of digital processing, along with scan and address methods used, plasma televisionscan generate symptoms that are unfamiliar to most technicians. The following troubleshooting techniques shouldhelp to isolate the cause in most cases. Documentation of unusual symptoms or known failures will be keptupdated on the ESI server. Check the service website at HTTP://service.sel.sony.com for the latest bulletinsregarding the model you are servicing.

Circuit failures in a plasma television generally fall into three categories:

1. Dead set

2. Protection events

3. No or distorted video

Units that exhibit no signs of operation require a few checks be done to determine if the power supply is at fault.The DE3 board contains the television micro-controller that is responsible for turning on certain switched voltageson the power regulator board along with telling the panel circuits to begin operating.Protect shutdown events are identified by the number of times the timer LED blinks. Most protect events arecaused by excessive current on a voltage line or the loss of a certain voltage.A no video condition requires elimination of the plasma panel and its associated drive circuits before analyzingthe video process circuits. The most important item to remember when servicing plasma displays is: If anylighting of the pixels is seen, the panel along with the scan and address boards are OK. It also indicatesthe presence of the required voltages for these circuits.Video distortions are easily isolated between the process circuits and panel/drive circuits by how they appear onthe screen. Panel failures will usually display a fixed distortion or missing video on a horizontal or vertical axis.Video process circuit failures tend to be more random and usually across the entire screen.Since all repairs are board level, each scenario above will be approached using flowchart diagrams to properlyisolate the failure to a particular board.Self-Diagnostics TroubleshootingFigure 3-4 shows a flowchart to aid in locating the cause of self-diagnostics indications displayed by the standby/power LED. A history of any diagnostics events can be viewed by pressing “Display”, “5”, “Volume –”, and the“Power” buttons, in order, on the remote commander when the unit is off.

42


FIGURE 3-4 - KE37/42XS910 DIAGNOSTICS TROUBLESHOOTING

Self-diagnostics indication

Four blinks ofSTBY/PWR LED?

No

Check connections tofan. Replace fan if

OK

Yes More than one fannot rotating?

Yes

Check for 14VDC at CN3pin 10 of Regulator board.Replace Regulator if not

present. Replace A boardif present

Replace Regulatorboard

No

No

Yes

Seven blinks?

No

Eight blinks?

Replace K boardYes

No

Yes

Replace DE2 board

Replace X-SUSboard

Yes

Nine blinks?Yes Panel alarm. Go to

"No Video" flowchartFigure 3-7

PDP01.3-4 4/20/04

5VDC at CN3 pin 9Regulator board?

Six blinks?

Troubleshooting a No Power ConditionIf a set fails to turn on or appears “dead”, the first item to check is whether the power supply is operational. TheRegulator board has a standby section generating a 3.3V and 5V source. If these are operating, the unit is not“dead”. The flowchart in Figure 3-5 is intended as a guide to determine if the Regulator board is at fault. One ofthe items referred to in the flowchart is a red and green LED located on the Interface board. The red LEDindicates standby while the green indicates power-on. This board is difficult to see but looking down the bottomof the regulator board from the top of the unit, a lit LED is easily detected. If unit is laying face down with the rearcover removed, the lower shield assembly holding the A board can be lifted after the screws are removed. This

43


FIGURE 3-5 - KE50XS910 POWER SUPPLY FLOWCHART

Unit will not power up

Is red or greenLED on Interface

board lit?

No

Is 3V (approx) onPin 4 of R6 on Interface

Board?Replace DE3 board

No

Does the symptomstill occur?

Finish

Replace Interfaceboard

3.3VDC atpin 11 of R1 onInterface board?

Replace PowerSupply board

No

Check Pin 2 of D17connector on DIGITAL

VIDEO assembly.

Yes

Is there 3.3V at thecheck point?

ReplaceDigital Video

board

Yes

Disconnect flexiblecable between D15 onDIGITAL VIDEO andR4 on INTERFACE

assembly. Clean edgecontacts of the flexiblecable and reconnect it

to the connectors.

Which LED is lit?

YesPower supply is onGo to "No picture

(black screen)" flowchart

Green(D4001)

Red (D4002)

Disconnect flexible cablebetween D15 on DIGITAL

VIDEO and R4 on INTERFACEassembly. Clean edge contacts

of the flexible cable andreconnect it to the connectors.

Yes

No

Does the symptomstill occur?

FinishNo

Replace Digital Video board

Yes

Is there 3.3V at Pin 11of D17 on D VIDEO?

ReplaceInterface

board

No

Yes

No

PDP01.3-5 3/18/04

is covered later in this chapter in the disassembly section. The red LED may be flashing three times and is avaluable indicator when troubleshooting a “no video” condition. It is mentioned in the flowcharts to follow. Figure3-6 shows the Interface board and the LED locations.

44


D4001 STBY (RED)D4002 PWR-ON (GREEN)

FIGURE 3-6 - LED INDICATORS ON INTERFACE BOARD

CAN BE VIEWED BY LIFTING A BOARDAND LOWER SHIELD ASSEMBLY

PDP01.3-6 3/18/04

45


Video Circuit TroubleshootingVideo circuit failures manifest themselves in two different ways: No video at all and abnormalities in the picturedisplay. In cases where no video is displayed, it is crucial to determine if the plasma panel is able to “prime”.Priming involves the generation of scan signals on the horizontal address lines to light the pixels just to the pointwhere they emit a small amount of light. Once this is accomplished, the address lines complete the necessary“firing” of each pixel to generate the appropriate level of each pixel color to reproduce an image. If the panel ispriming, it is a good indication that everything is OK with the glass panel and associated drive circuits. Focus willnow turn to the video process circuits.

If the panel is not priming and there is audio, a check of the required voltages is necessary to eliminate powersupply line failures as the cause. The presence of audio is an important clue as it indicates the power supply isturning on. Several voltage lines specifically allocated to the panel drive circuits are monitored for low voltageconditions. Any failure of these monitored lines will cause the interface board to enter a “protect” status. Whenthis occurs, the red LED on the Interface board will be flashing in sequences of three.

A panel alarm may also be indicated by the standby/power LED. It will be flashing in sequences of nine. This isusually caused by an over-current condition and the likely suspect is a shorted scan drive IC. These driversusually exhibit signs of overheating damage with burn holes and cracks appearing on their surface. The paneldesign used in this model incorporates the drivers on two boards permanently attached to the flexible cables,which are part of the glass panel. Replacement of the panel is required if this occurs.

Figures 3-7, 3-8 and 3-9 contain flowcharts to assist in isolating the cause of a “no video” condition caused by afailure of the panel to light or “prime”.

If the problem is determined to be in the video process circuits, the A, DIC2 and DE3 boards must be isolated asthe cause. The flowchart in Figure 3-10 will provide assistance.

46


No videoNo panel priming

Is red LED onInterfaceboard lit?

Power supply problemGo to "No Power"flow chartFig 3-5

Is D4002flashing 3X?

*Connect pin 7 of R6(MASK) on INTERFACE

board to GND

Does the screendisplay full white

Image?

Replace Interface board.

Is normal picture nowdisplayed on screen?

Finish

No

Yes

No

There is a missing voltage. Go tothe flowchart in Figure 3-8 for

further diagnosis

Check D5401 and D5402(red and green LED) onDIGITAL VIDEO board

Yes

No

6.5VDC pin 7 ofconncetor R1 onInterface board?

Check PowerSupply board

No

Yes

Input signal problem. Go tovideo process flowchart in

Figure 3-10

No

Yes

Are theseLEDs lit?

Replace DigitalVideo assembly

No

Yes

Switch S5201 onDigital Video board

set to normal?

Set the SW tonormal

No

Replace Y-SUSboard

Does thesymptom still

occur?

Yes

Finish

Replace X -SUSboard

Yes

No

Yes

* A 10K resistor to ground will producecolor bar pattern

GND = white screen10K = color bars

R6

FIGURE 3-7 - NO VIDEO TROUBLESHOOTING FLOWCHART PDP01.3-7 3/9/04

47


FIGURE 3-8 - KE50XS910 POWER SUPPLY WARNING

Red LED (D4002) onDigital Video board

flashing 3 times

Check VSUS (215-22-V)and VADR (55-60V) on

Power Supply.*

Which voltageis low or missing?

Disconnect Y4 connector on Y Driveboard. Re-check VSUS voltage.

Reconnect Y4 connector on Y Drive& disconnect X2 connector on XDrive. Re-check VSUS voltage

Replace X Driveassembly

No

Disconnect D2 connector onDigital Video board. Re-

check VADR voltage.

Yes

VADR

Is the VSUSvoltage normal?

Yes

VSUS

Yes

Is the VADRvoltage normal?

ReplacePanel assembly

Yes

Check resistance between PSUSand VH on Y Drive assembly

No

Short?(normally highimpedance)

Yes

Scan-Drive IC shortedReplace panel

Replace Power Supplyassembly

Go to "Missing LowVoltage" flowchart

Fig 3-9

NOTE: Should check within afew seconds before shutdown

No

Replace PowerSupply assembly

No

Is the VSUSvoltage normal?

Replace Y Driveassembly

No

PDP01.3-8 3/18/04

*V-SUS CN8 pin 9VADR CN12 pin 1

Power Supply Board

NOTE: Should check within afew seconds before shutdown

PSUS & VH TEST POINTNOTE: Should check within afew seconds before shutdown

Set switchSW5201 to "off". LED

still blinkng?

48


FIGURE 3-9 - KE50XS910 LOW VOLTAGE TROUBLESHOOTING

Low voltage WarningRed LED on interface

board flashing 3X

3.3VDC at TP K2038on Y-SUS board?

Replace Y Driveassembly.

Yes

Set switch S5201 oninterface board to "OFF"

3.3VDC atTP K1017 on

X-SUS board?

Replace X Driveassembly.

Yes

16.5VDC atconnector X2 pin on

X-SUS board?

Replace DigitalVideo assembly.

Has red LEDstopped blinking?

Finish

No

Yes

No ReplaceINTERFACE

assembly.

No Replace PowerSupply assembly

No

Yes

PDP01.3-9 3/9/04

49


FIGURE 3-10 - KE50XS910 VIDEO PROCESS TROUBLESHOOTING

No videoPanel is primed, audio OK

Can OSD bedisplayed?

No

Re-seat connector

Yes

Picture on rightside when TwinView engaged?

Replace DIC2 board

LVDS connectorfrom DE2 to Logicboard connected?

YesReplace DE3 board

No

No

Yes

No

No

Does componentvideo input display

picture?Replace DIC2 boardYes

Can picture fromMemory Stick be

displayed?

Yes Replace A board

Replace DIC2 board

PDP01.3-10 3/23/04

50


FIGURE 3-11 - DM BLOCK LVDS CONNECTORS

DM BLOCK

REMOVEPLASTIC COVER

LVDSCONNECTORS

PDP01.3-11 3/9/04

NOTE: The DIC2 and DE3 boards are enclosed within a shielded assembly known as the DM block. In order toaccess these boards for removal, the shield assembly must be taken apart. There is a LVDS cable connectingthe two boards and this cable is looped outside of the shields. It is protected by a plastic cover. It is veryimportant to remove this plastic cover and unplug both ends of the LVDS cable before attempting to separate theboards from the housing. Failure to do so will cause the shield to snag the LVDS connectors and damage them.The connectors are easily removed by pinching the release tabs and pulling them out. This is shown in Figure 3-11

Troubleshooting Display Panel AbnormalitiesSymptoms appearing on the screen during panel and drive circuit failures are generally easy to identify. Sincethe panel is controlled by intersecting scan and address lines, distortions, abnormal colors or missing pixel datawill manifest themselves as horizontal or vertical lines and may occur in entire blocks. If you have acquired onlythis chapter for troubleshooting the KE50XS910 model, obtain the section in Chapter 1, which contains additionalinformation applying to general plasma theory and troubleshooting.

In Figure 3-12, some examples of address circuit failures are shown. If one or more vertical lines of videoinformation are missing or filled with a solid color, the panel will likely have to be replaced. Note the use ofaddress boards and drive ICs on the upper and lower ends of the panel. This model uses a “dual-scan” panel.Address control is shared so that the upper and lower drivers scan half of the panel. Another unique feature ofthe panel used in this model is the display of white whenever drive information is lost for the address line(s).Most panel designs display a dark section whenever a drive failure occurs so this is important to remember forthis model.

Single line failures are caused by problems in the drive outputs. Since the drivers are mounted to the FPCassembly, the panel must be replaced. Multiple lines of missing video creating a block of no information can becaused by the Digital Video or Address boards. It is unlikely that three drive ICs have failed. Suspect theaddress board first, followed by the Digital Video board. If an entire block of video is missing, the address drivesignals can be swapped to see if the block can be moved to another area of the screen. The Digital Video boarddistributes the drive information to all of the Address boards and there is sufficient movement in the FPC cablesto accomplish this. If the missing block of video remains in the same location, one of the address drive ICs hasfailed and the panel must be replaced. If the block can be moved, the Digital Video board is at fault.

Figure 3-13 illustrates potential symptoms that might be seen if a failure occurs in the scan drive circuits. Thescan drive ICs are mounted to a pair of circuit boards that has the FPC cables bonded to them. Any singlemissing lines of video will require a panel replacement. If one-half of the picture is missing information, examinethe drive ICs on the FPC adjacent to the failure for signs of overheating to determine whether the panel or Y-SUSboard should be replaced.

51




XSUSBOARD

DIGITAL VIDEOBOARD

YSUSBOARD

INTERFACEBOARD

SCAN DRIVERBOARDS

FPC

FPC

FPC

FPC

FIGURE 3-12 - KE50XS910 PANEL ADDRESS FAILURES PDP01.3-12 3/8/04

BLANK OR DIFFERENTCOLORED LINES

MISSING BLOCK OF VIDEO

NOTE: Whenever a scan drive IC fails, no output will appear from that IC or any of the succeeding drivers onthat board. If the top IC on one board were to fail, only half of the video would be displayed.

52




XSUSBOARD

DIGITAL VIDEOBOARD

YSUSBOARD

INTERFACEBOARD

SCAN DRIVERBOARDS

FPC

FPC

FPC

FPC

FIGURE 3-13 - KE50XS910 PANEL SCAN FAILURES

SINGLE HORIZONTAL LINESOF MISSING VIDEO

MULTIPLE HORIZONTAL LINESOF MISSING VIDEO

DEFECTIVE IC

PDP01.3-13 3/8/04

DisassemblyOverviewThis section will cover the required steps to disassemble the unit down to panel replacement. Due to the largenumber of screws involved, be sure to have a container in which to place them during the procedure. It isextremely important to place the plasma television on a repair stand of adequate size along with a piece of foampadding to protect the screen. Be certain the padding is at least ¾ of the screen size to prevent flexing of theglass panel, which is easily damaged. The glass can withstand moderate bending but the barrier ribs separatingthe vertical lines of pixels are easily damaged by minor flexing.


53


REMOVE TWO 4x16 SELF-TAP

FIGURE 3-14 - KE50XS910 SPEAKER COVER REMOVAL PDP01.3-14 3/9/04

Speaker Housing and Rear Cover RemovalAs shown in figure 3-14, remove the left and right rear speaker secured by two 4X16 self-tap screws each. Therear cover screws will now be exposed. Remove the following screws for the rear cover:

• Four 5X40 machine (black) securing the stand. The stand must be removed first.

• Fourteen 4X16 black, self tap (black)

• Eight 3X6 machine (black)

• Six 4X10 machine (black)


54


Y-SUS BOARDREGULATOR

BOARD X-SUS BOARDDIGITAL VIDEO

BOARD

DM BLOCKDIC2, DE3BOARDS

Y-SUS BOARD A BOARD(UNDER SHIELD)

FIGURE 3-15 - KE50XS910 CIRCUIT BOARDS PDP01.3-15 3/9/04

A Board and DM Block RemovalFigure 3-16 illustrates the location of the video input and processing circuit boards. The cover over the videoinput jacks must be removed. This cover also secures the AC input receptacle. The earth ground wire must alsobe removed as shown. The metal shield above the input connectors covers the A board. Use caution whenremoving the nylon lock nuts as it is easy for them to fall out when lifting the shield.The DM block must be removed after the video input cover and A board shield since it attaches to the A boardwith a large connector (CN8001). Remove two connectors CN1813 and CN1814 (not shown) at the bottom ofthe DM block. Loosen the four machine screws securing the DM block and GENTLEY lift it from the A board.There is a LVDS connector located on the upper part of the DM block connected to the Interface board. LVDScables use thin wires. They are easily damaged. Remove the two LVDS and one communication connector asshown in Figure 3-17.

Once the rear cover has been removed, the view shown in figure 3-15 is seen. The Y-SUS, X-SUS, Scan Driveand Address boards are not visible as they are located under the shields. Use this view as a guide when re-assembling the unit to properly dress the cable harnesses.

55


REMOVE FOUR 6x12SELF-TAP SCREWS AND

GROUND WIRE

REMOVE TWO 3X6 MACHINESCREWS AND NYLON LOCK

PINS

FIGURE 3-16 - VIDEO INPUT COVER AND SHIELD REMOVAL

REMOVE NUTSSECURING DVICONNECTOR

PDP01.3-16 3/8/04

MEMORY STICK LVDSCONNECTOR

DE3 TO LOGICBOARD LVDSCONNECTOR

COM CONNECTOR

FIGURE 3-17 - DM BLOCK REMOVAL PDP01.3-17 3/8/04

If the DM block is not going to be serviced, it can be rested on top of the PSU board. There are several powercables between the DM and PSU and this avoids unnecessary removal.

56


CN8003

CN8002

CN8005

CN8601

CN8230

FIGURE 3-18 - KE50XS910 A BOARD REMOVAL

CN8001

PDP01.3-17 3/8/04

CN3062

CN3001

CN3061GROUND

CONNCETOR

FIGURE 3-19 - KE50XS910 K BOARD REMOVAL PDP01.3-19 3/9/04

In Figure 3-18, removal of the A board is shown. The listed connectors are removed along with the RF inputcable to the tuner. Four 3X6 machine screws secure the board. Remove the board and place in a safe location.

K Board RemovalIn Figure 3-19, removal of the K board is shown. The board has a shield on top that has been removed. Theshield is secured with two 3X6 machine screws. The bottom shield securing the K board is attached to thechassis with four 3X6 machine screws. Remove the three cable and two ground connectors as shown. Removethe cables from the purse-lock retainers. Unplug all connectors attaching cables to cables. Set cable harness tothe right side and out of the way.

57


CN11

CN6

CN3

CN7

CN2

CN9 CN8 CN12

CN4 CN10 CN5 CN1

FIGURE 3-20 - KE50XS910 POWER SUPPLY BOARD PDP01.3-20 3/8/04

REMOVE FOUR 3X6MACHINE SCREWS

LOOSEN SELF-TAPPING SCREWS

FIGURE 3-21 - LOWER SHIELD REMOVAL PDP01.3-21 3/8/04

Power Supply RemovalFigure 3-20 illustrates the power supply (Regulator) board. The board is secured by seven 3X6 machine screws.If the board is going to be removed for replacement of the panel, the connectors from the DM block can remainconnected. Place the DM block on top of the Regulator board and remove together.

Lower Shield RemovalIf the panel is going to be replaced, the lower shield assembly that held the A board and DM block must beremoved. Figure 3-21 illustrated this. It is secured by four 3x6 machine and two 3X12 self-tapping screws. Theself-tapping screws only need to be

58


REMOVE FOUR3x6 SCREWS

REMOVE FIVE3x6 SCREWS

REMOVE TWO3x6 SCREWS

FOR GROUND

CONNECTORCN2301 UNDER

SHIELD

FIGURE 3-22 - KE50XS910 Y-SUS SHIELD REMOVAL PDP01.3-22 3/8/04

DISCONNECTSPEAKER

REMOVE NINE3X6 SCREWS

REMOVE 3X6SCREW FOR

GROUND

DISCONNECTSPEAKER

FIGURE 3-23 - KE50XS910 X-SUS SHIELD REMOVAL PDP01.3-23 3/8/04

DISCONNECTFAN

CONNECTORCN1201 UNDER

SHIELD

Y-SUS and X-SUS Shield RemovalFigure 3-22 shows the Y-SUS board shield and its removal procedure. This shield must be removed to accessthe Y-driver boards and ICs for inspection and/or replacement. This photo shows the K board installed. Unlessthe K board needs replacement, it can be left intact. Nine 3X6 machine screws are securing the unit. Two 3X6machine screws for ground connections must also be removed. Unplug the cooling fan connector. When liftingthe shield, note the cable for CN2301. This must be unplugged from the Y-SUS board before the shield can beremoved completely. Note the layout of all wiring for proper re-assembly.

Figure 3-23 demonstrates the removal of the X-SUS shield. Remove ten 3X6 machine screws (nine securing theboard and one for a ground connector). Note the layout or the wiring in the purse-lock retainers and the removalof ground connections for reference when re-installing the shield.

59


REMOVE THREE 4X16GOLD SELF-TAP

SCREWS

FIGURE 3-24 - KE50XS910 PANEL SIDE SCREWS PDP01.3-24 3/8/04

Panel RemovalOnce all of the above circuit boards and shields have been removed, the panel is ready for removal. Two largebrackets are attached to the panel with four 5X10 machine screws. Although the brackets do not come with thepanel, they should be left intact to ease the removal. The replacement panel will come with disposable bracketsto assist in installation. The original brackets can then be transferred to the new panel.Remove three 4X12 self-tap screws on the left and right sides of the panel as illustrated in Figure 3-24. Next,remove four, 4X8 machine and four 4X12 self-tap screws securing the bracket to the top and bottom of the filterglass assembly as illustrated in Figure 3-25.

60


REMOVE FOUR 4x6MACHINE SCREWS AT TOP

REMOVE FOUR 4x16 SELF-TAP SCREWS AT BOTTOM

FIGURE 3-25 - KE50XS910 UPPER AND LOWER PANEL BRACKETSPDP01.3-25 3/23/04

SECURE SPEAKER WIRES ANDCONNECTORS ON BOTH SIDES

TO CABINET

PDP01.3-26FIGURE 3-26 - KE50XS910 SPEAKER CONNECTORS 3/23/04

Although the service manual includes the removal of the speaker assemblies for panel replacement, it is notnecessary. It is easier to leave the speakers intact since the left and right gaskets for the panel rest on the edgeof the speaker housings. It is important to secure the speaker connectors with a piece of tape since they will tendto fall onto the filter glass and get in the way when the new panel is installed. This is demonstrated in Figure 3-26

61


FIGURE 3-27 - KE50XS910 PANEL REMOVAL PDP01.3-27 3/8/04

The panel can now be lifted from the filter glass assembly and demonstrated in Figure 3-27.NOTE: Panel replacement should only be performed in the shop. The removal of a large number of self-tapscrews creates a considerable amount of plastic contaminants. Accumulated dust along with the plastic piecescan easily fall onto the backside of the filter glass. This must be thoroughly removed using air from a compressor.It is extremely important to remove all contaminants before installing the new panel.The KE50SX910 is unique in that the replacement panel does not come with the digital, interface, address andscan drive boards installed. All circuit boards must be transferred to the replacement panel. As of the writing ofthis manual, the policy regarding panel replacement of this model has not been determined. This is mainly dueto the requirement of an interface jig to adjust the scan and address voltages for the replacement panel. Checkfor the latest information regarding this matter on the ESI website.

Y-SUS and X-SUS Board RemovalShould the need arise to replace the Y-SUS or X-SUS boards, removal is illustrated in Figure 3-28 for the Y-SUSboard and Figure 3-29 for the X-SUS board. Note Figure 3-28 and the location of the panel serial number label.Also note the Y-Scan drive ICs located on the two circuit boards attached to the panel.

62


FIGURE 3-28 - KE50XS910 Y-SUS BOARD PDP01.3-28 3/8/04

FIGURE 3-29 - KE50XS910 X-SUS BOARD PDP01.3-29 3/8/04

63


FIGURE 3-30 - KE50XS910 INTERFACE AND DIGITAL VIDEO BOARDSPDP01.3-30 3/8/04

CABLES ON DIGITAL VIDEOBOARD CAN BE SWAPPED TO

TROUBLESHOOT PANELADDRESS PROBLEMS

Interface and Digital Video BoardsFigure 3-30 illustrates the location of the Interface and Digital Video boards. Note the seven FPC cables that areidentical in size. These are the sources of address information to the address drive boards. The cables can beswapped in order to determine if a section of missing video is caused by the address drivers or the Digital Videoboard.

64

4. Troubleshooting the KDE42/50/61XBR950

Chapter 4 - Troubleshooting the KDE42/50/61XBR950OverviewThe key difference between the XBR950 and XS910 model series is the use of an external “Media Box” toreceive NTSC and ATSC broadcast signals. The tuner and decoding circuitry is also capable of receiving andprocessing Quadrature Amplitude Modulation (QAM) used by cable companies to encode the audio and videoinformation for transmission. The media box also receives the external input sources including composite, S-Video, component and DVI sources. It is not serviceable in the field. Replacement of the entire unit is requiredif a failure occurs.

The plasma display panel in the XBR950 models functions as a monitor device only. The lack of internal videoand audio processing circuits reduces the amount of on-board circuitry and wiring. This makes it easier todiagnose and service the display assembly.

This chapter will point out the circuits that are unique to this model along with a description of each board’sfunction. Practical troubleshooting methods will be discussed followed by a systematic procedure for disassemblingand re-assembling the unit. Plasma televisions rely on a large, gassed-filled glass panel to generate video. It isimportant that this glass panel be properly braced and secured by brackets and the back cover assembly. Aconsiderable amount of shielding is also required due to the high voltage levels generated by the scan drivers.Because of this, a large number of screws are utilized.

Plasma Panel Block DiagramAudio/Video InputAs illustrated in Figure 4-1, audio and video information is input to the panel assembly from the Media ReceiverBox. The audio and video arrive on two separate cables. The audio cable is black and the video white. The DEMboard receives this data and functions as an interface between the incoming protocol and the format used by theDigital Board for control of the scan and address lines for the panel.

Audio information is received from the Media Box via UART protocol (Universal Asynchronous Receiver/Transmitter). The information is received by differential transmission known as LVDS. The DEM board routesthe data to the K board (not shown) for audio processing and amplification.

Video information is received via DVI-D, a differential digital RGB format. This information is processed by aTDMS receiver and sent to circuitry to scale the incoming video to conform to the panel resolution. Control databetween the Media Box and panel is carried by the audio cable while HDCP key data is handled by the videocable.

The Digital board processes and allocates the RGB information for application to the address control lines.Timing for the scan drivers is also generated here.

Panel Drive CircuitsA “dual-scan” panel is used in this chassis. Addressing control is achieved by placing de-multiplexing and drivercircuits at the top and bottom of the plasma panel. Each row of address drivers is responsible for controlling onehalf of the screen. The High Voltage board (known as Y-SUS in other panel designs) generates properly timedpulses to activate each scan line as needed to coincide with the address information.

Each of the four Data Relay boards contains six drive ICs. Each drive IC receives multiplexed data. This data isde-multiplexed, expanded and amplified for each address line of the panel. The number of lines per drive ICvaries upon the horizontal resolution of the panel based on its size. The drive ICs are mounted on the flexible PCcables, which are integrated with the glass panel. A failure of any of these drivers requires replacement of thepanel.

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DATA RELAY BOARD DATA RELAY BOARD


PLASMA PANELCOMMON

RELAYBOARD

DIGITAL BOARD

HIGHVOLTAGEBOARD

DEM BOARDFROMMEDIABOX

SCAN DRIVERBOARDS

AUDIODATA

VIDEODATA

G2 BOARDPOWER SUPPLY

AC IN

TO PANELBOARDS

FIGURE 4-1 KDE42/50/61XBR950 PLASMA PANEL BOARDS PDP01.4-1 3/9/04

G1 BOARDPFC

(61" 0NLY)

The High Voltage board generates timed scan pulses (also multiplexed) to the scan drive ICs in the Scan Driveboard. The flexible PC cables from the panel do not have the drivers mounted on them as do some paneldesigns. They are attached to the Scan Drive board with locking connectors. If a scan drive IC failure occurs,the board can be replaced.

A more in-depth look at plasma display theory and general troubleshooting is available in Chapter 1 of the PDP-01 training manual.

Protection and Self-DiagnosticsThe panel-drive and power supply circuits are monitored for over-current or under-voltage conditions. If a failureoccurs on one of these monitored lines, the power/standby LED will flash a designated number of times dependingon which line a fault was detected. Below is a list of possible fault indications:

66


• LED blinks red and green alternately: A panel error is indicated. A missing voltage or over-currentcondition on the panel drivers has been detected.

• Four blinks: An over-temperature condition exists. The panel is monitored to protect againstoverheating.

• Six blinks: VD (70VDC) on the power supply is not present. This usually indicates an inoperativepower supply.

• Seven blinks: DC voltage has been detected on one or more of the speaker lines. Audio drive ICfailures are usually the cause.

TroubleshootingDue to the large amount of digital processing, along with scan and address methods used, plasma televisions cangenerate symptoms that are unfamiliar to most technicians. The following troubleshooting techniques shouldhelp to isolate the cause in most cases. Documentation of unusual symptoms or known failures will be keptupdated on the ESI server. Check the service website at HTTP://service.sel.sony.com for the latest bulletinsregarding the model you are servicing.

Shutdown - Self-Diagnostics Indication

The flowchart in Figure 4-2 will assist in locating the cause of a protect event with blinking LED.

FIGURE 4-2 - KDE42/50/61XBR950 SELF-DIAGNOSTICSTROUBLESHOOTING

Protection shutdownPWR/STBY LED flashing

Red and greenalternating blinks?

No

Go to Figure 4-3No video flowchart

Yes

Seven blinks? Replace K board

TP3804 on DEM board

momentarily low?

Yes

Disconnect and re-connect AC power

to panel

No

Yes

No

Six blinks?*VD (70VDC) missing

Replace PowerSupply board

Yes

Four blinks?Yes

If LED stops blinking after power isturned off and then back on, panel

temperature reached limit. If protectionreturns immediately, thermal sensor is

disconnected or has failed

No

Replace DEM board

* VD can be checked atCN1010 pin 6 on Power

Supply board.

PDP01.4-2 4/20/04

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FIGURE 4-3 - KDE42/50XBR950 NO VIDEO TROUBLESHOOTING

No video on display

Panel priming?Input signal problem.

Check Media Box andconnections to panel.

Panel alarm?

Glass envelope of panelcompromised. Replace panel

No

Yes

No Replace PowerSupply board

Yes

VD (70VDC) atCN12-1 on Data

Relay board?

No

Yes

No

Yes

*VS (190VDC)present at Y Drive

boards?

VS (190VDC)present at CN101-9

Power Suuply?

Yes

Replace G board

No

*VS test pointMeasure across

Check for damagedscan drive IC's. ReplaceScan Drive board and

HV board if found.

Disconnect CN12 fromData Relay board

VD (70VDC) atCN1010-6 on G

board?

Replace G board

No

Check fordamaged driveIC's on address

cables.

Yes

IC damage?

Replace shortedData Relay board

Replace panel

Burnt Address drive IC

PDP01.4-3 3/18/04

Troubleshooting “No Video”

Failures of the plasma display can appear as no video or abnormalities in the displayed image. In cases of a“no video” symptom, it is important to determine if the panel is “priming”. Priming is a term describing the dimlighting of the pixels, which produce a dark gray background raster similar to a CRT display. Ambient lightingmay make it difficult to detect. Turning the unit on and off and observing the screen helps to tell the differencebetween a “true black” and primed panel.

NOTE: It is important to determine panel priming if no video is displayed. The presence of priming indicatesthe scan drive circuits are operational and the required voltages are present. The media box and/or theconnections between it and the panel are suspect.

The flowchart in Figure 4-3 will assist in locating a “no video” condition.

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PLASMA PANELCOMMON

RELAYBOARD

DIGITAL BOARD

HIGHVOLTAGEBOARD


SCAN DRIVERBOARDS

AUDIODATA

VIDEODATA

FIGURE 4-4 - KDE42/50/61XBR950 PANEL ADDRESS FAILURES PDP01.4-4 3/10/04

Troubleshooting Display Panel AbnormalitiesSymptoms appearing on the screen during panel and drive circuit failures are generally easy to identify. Sincethe panel is controlled by intersecting scan and address lines, distortions, abnormal colors or missing pixel datawill manifest themselves as horizontal or vertical lines and may occur in entire blocks. If you have acquired onlythis chapter for troubleshooting the KDE42/50/61XBR950 models, obtain the section in Chapter 1 of the entiremanual (PDP-01), which contains additional information applying to general plasma theory and troubleshooting.

In Figure 4-4, some examples of address circuit failures are shown. If one or more vertical lines of videoinformation are missing or filled with a solid color, the panel will likely have to be replaced. Note the use ofaddress boards and drive ICs on the upper and lower ends of the panel. This model uses a “dual-scan” panel.Address control is shared so that the upper and lower drivers scan half of the panel.

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BURNT SPOT ON DRIVE IC

FIGURE 4-5 - DAMAGED ADDRESS DRIVE IC PDP01.4-5 3/12/04

Single line failures are caused by problems in the drive outputs. Since the drivers are mounted to the FPCassembly, the panel must be replaced. Multiple lines of missing video creating a block of no information can becaused by the Digital Video or Address boards. If the missing video covers an area larger than what is controlledby a single drive IC, suspect the Address Relay board. It is unlikely that more than one drive IC has failed. Closeexamination of the flexible PC cable in the affected are should be performed. Look for shorts or corrosionbetween the pads of the cable or signs of overheating of the drive IC mounted on the cable. This is illustrated inFigure 4-5.

Figure 4-6 illustrates potential symptoms that might be seen if a failure occurs in the scan drive circuits. Thescan drive ICs are mounted to a pair of circuit boards, each controlling half of the screen. Failures occurring onany of the drive ICs will cause a loss of scan on any subsequent drivers below the failed IC. For example, if thesecond IC from the top on the upper address board fails, no video will appear from that point to the middle of thescreen. Any single missing lines of video will require a panel replacement. Damaged drive ICs will usually causea panel alarm failure if excessive current is being drawn. Whether or not there is a panel warning, both ScanDrive boards should be examined closely for any signs of overheating. This can appear as cracks or holes onthe surface of the IC. Figure 4-7 illustrates an example of a failed IC.

NOTE: The locks securing the flexible PC cables from the panel to the driver board are delicate and easilydamaged when attempting to release the cable. By removing the Scan Drive board and twisting it as shown inFigure 4-8, all four locks can be disengaged at once by using the cables to lift the lock tabs.

Due to the short length and radius of the bend on the FPC cables, they are difficult to re-insert. When re-installing the cables, close the lock tab almost to the point of locking and insert the cable into the slot of the tab.Lift the lock tab slightly with one hand and push the cable in until seated. Press the lock tab firmly to secure andcheck to see if the cable is locked. If the cable is inserted properly, you should not be able to see the contactpads.

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PLASMA PANELCOMMON

RELAYBOARD

DIGITAL BOARD

HIGHVOLTAGEBOARD


SCAN DRIVERBOARDS

AUDIODATA

VIDEODATA

FIGURE 4-6 - KDE42/50/61XBR950 PANEL SCAN FAILURES PDP01.4-1 3/9/04

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FIGURE 4-7 - DAMAGED SCAN DRIVE IC PDP01.4-7 3/12/04

BURN HOLE

CRACK

FIGURE 4-8 - UNLOCKING FLEX CABLES FROM DRIVER BOARDPDP01.4-8 3/12/04

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REMOVE SPEAKER COVERS ONBOTH SIDES

FIGURE 4-9 - KDE42/50XBR950 SPEAKER COVER REMOVALPDP01.4-9 3/12/04

DisassemblyOverviewThis section will cover the required steps to disassemble the unit down to panel replacement. Although thischapter covers the 42, 50, and 61-inch models, disassembly of the KDE61XBR950 will be covered in Chapter 5due to the significantly different design of the components housing the panel.

Due to the large number of screws involved, be sure to have a container in which to place them during theprocedure. It is extremely important to place the plasma television on a repair stand of adequate size along witha piece of foam padding to protect the screen. Be certain the padding is at least ¾ of the screen size to preventflexing of the glass panel, which is easily damaged. The glass can withstand moderate bending but the barrierribs separating the vertical lines of pixels are easily damaged by minor flexing.


Speaker Housing and Rear Cover RemovalAs shown in Figure 4-9, remove the left and right rear speaker covers secured by two 4X16 self-tap screws each.The rear cover screws on both sides will now be exposed. Remove the following screws for the rear cover:

• Twenty 4X16 black, self tap (black)

• Three 3X8 machine (black)


73


K BOARD POWERSUPPLY BOARD

HIGH VOLTAGEBOARD

DEM BOARD

FIGURE 4-10 - KDE42/50XBR950 CIRCUIT BOARD LOCATIONSPDP01.4-10 3/11/04

UPPER ANDLOWER SCAN

RELAY BOARDS

FIGURE 4-11 - DISCONNECT DEM BOARD

REMOVECN3801 (LVDS)

REMOVECN3302 AND

CN3303

REMOVE CABLESFROM RETAINERSAND PLACE ASIDE

PDP01.4-11 3/12/04

Once the rear cover has been removed, the view shown in Figure 4-10 is seen. The High Voltage (Scan), ScanDrive, DEM, K and Power Supply boards are easily visible. Note the long, flat metal brackets covering the upperand lower DPC cables connected to the data relay boards. These function as heat sinks for the drive ICsmounted to the cable. Use this view as a guide when re-assembling the unit to properly dress the cable harnesses.

DEM, K and Power Supply Board RemovalRemoval of these boards can be accomplished as one assembly. They are mounted on an assembly andattached by three brackets to the display panel. Once the necessary connectors are removed, the bracketscrews can be removed and the entire assembly lifted out of the unit. Be careful to lift the assembly straight upand avoid any unnecessary flexing to avoid stress to the Power Supply board. Figures 4-11, 4-12, 4-13 and 4-14illustrate the necessary connectors to remove. Figure 4-15 illustrates the screws securing the four brackets to beremoved. Once this is done, the entire assembly can be lifted out.

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FIGURE 4-12 - DISCONNECT POWER SUPPLY BOARD PDP01.4-12 3/11/04

REMOVE CN1009AND CN1010. REMOVEFROM PURSE LOCKS

AND SET ASIDE.

FIGURE 4-13 - SPEAKER CONNECTOR REMOVAL PDP01.4-13 4/20/04

REMOVE LEFT AND RIGHTSPEAKER CONNECTORS.

PEEL GROUND TAPE BACKFROM PANEL

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FIGURE 4-14 - THERMAL SENSORS REMOVAL PDP01.4-14 3/12/04

DISCONNECT SENSORFROM PANEL ABOVEREGULATOR BOARD

UNPLUGG SENSORFROM HIGH VOLTAGE

BOARD

REMOVE EIGHT 4x16 SELF-TAPSCREWS AND LIFT ENTIREASSEMBLY FROM PANEL

FIGURE 4-15 - PANEL BRACKET REMOVAL PDP01.4-15 3/12/04

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FIGURE 4-16 - PANEL ASSEMBLY AND BOARD LOCATIONS PDP01.4-16 3/12/04

UPPER DATARELAY BOARDS

HIGH VOLTAGE(SCAN) BOARD

COMMON ANDRELAY RETURN

BOARDS

LOWER DATARELAY BOARDSLOGIC BOARD

PANEL TYPE ANDSERIAL #

VS & VA VOLTAGES

CN1009

CN1006

CN1010

+

+

RV1701VS ADJ

RV1501VD ADJ

TP1501VD

TP1701VS

G BOARD

FIGURE 4-17 - VS AND VD ADJUSTMENT

Panel RemovalOnce the brackets and boards have been removed, the panel control and drive boards can be viewed as shownin Figure 4-16. Once this stage has been achieved, the entire panel assembly can be lifted out if replacement isnecessary. Note the location of the labels containing the panel-type and serial number information. Thesenumbers will be necessary to record if the panel is to be replaced. The required Vs and Vd voltages for thatparticular panel are also located here. If a new panel is installed, it will have the high voltage, address and logicboard installed. If the G board is replaced, the voltages on the new board must be adjusted to the existing panel.Figure 4-17 illustrates the locations of the test points and variable resistors for these adjustments.

NOTE: Panel replacement should only be performed in the shop. The removal of a large number of self-tapscrews creates a considerable amount of plastic contaminants. Accumulated dust along with the plastic piecescan easily fall onto the backside of the filter glass. This must be thoroughly removed using air from a compressor.It is extremely important to remove all contaminants before installing the new panel.

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FIGURE 4-18 - HIGH VOLTAGE BOARD PDP01.4-18 3/12/04

TEMPERATURESENSOR

High Voltage and Common Board RemovalThe High Voltage board is shown in Figure 4-18. Thirteen 3X6 machine screws secure it to the panel. Once thewired connectors are removed, the board can be lifted slightly and pulled away from the scan drive boards. Donot forget to remove the thermal sensor located on the large heat sink, as the new board does not come withone.

Whenever the High Voltage board is replaced, four different voltages must be checked and re-adjusted asnecessary. These voltages vary from panel to panel. Many of the panels do not have a label defining thesevoltages although newer productions will. If the panel has such a label, it will be located on the rear of the paneljust above the Common Relay board. It will define the following voltages, which can fall into these specifiedranges:

• VBW: 90 or 100VDC

• VP: 194 to 233VDC

• VSW: 160 or 170

• -VW: -60 to –79VDC

Note: If the panel does not have a label, the Technical Support line will need to be called. Provide the panel typeand serial number from the label at the top right corner of the panel and the proper voltages can be looked up ina database.

78


Figure 4-19 illustrates the adjustment and test point locations for the voltages listed above. They are located onthe High Voltage Board.

FIGURE 4-19 - VOLTAGE ADJUST AND TEST POINTSPDP01.4-18

VBW ADJ ANDTEST POINT

VP ADJ ANDTEST POINT

VSW ADJ ANDTEST POINT

3/23/04

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5. Disassembling the KDE61XBR950

Chapter 5 - Disassembling the KDE61XBR950

OverviewThe KDE61XBR950 is unique when compared to the KDE42/50XBR950 in that its panel design is different. Thevideo processing and panel control circuits are the same. The troubleshooting procedures for video and paneldrive in the 42/50-inch models apply to the 61" model. An additional power supply board is used in theKDE61XBR950. It is called the G1 board. It contains a PFC (Power Filter Control) circuit to boost and stabilizethe rectified AC. This is sent to a G2 board, which is similar to the G board used on the smaller models.

This chapter will focus on proper disassembly of the 61" model. The panel is secured to the filter (front) glass ina different manner. The disassembly procedure is also quite different.NOTE: Due to the large amount of digital processing along with scan and address methods used, plasmatelevisions can generate symptoms that are unfamiliar to most technicians. The following troubleshootingtechniques should help to isolate the cause in most cases. Documentation of unusual symptoms or knownfailures will be kept updated on the ESI server. Check the service website at HTTP://service.sel.sony.com for thelatest bulletins regarding the model you are servicing.

A large number of screws will be removed so be sure to have a container in which to place them during theprocedure. It is extremely important to place the plasma television on a repair stand of adequate size along witha piece of foam padding to protect the screen. Be certain the padding is at least ¾ of the screen size to preventflexing of the glass panel, which is easily damaged. The glass can withstand moderate bending but the barrierribs separating the vertical lines of pixels are easily damaged by minor flexing.


Disassembling the KDE61XBR250Rear Cover RemovalRemoval of the rear cover does not require disassembly of the speaker housings as in some models. All rearcover screws are machine type. Remove the following screws and lift the rear cover off:

• Twenty 4X12 machine screws securing the perimeter.• Five 3X8 machine screws securing the A/V input jacks.• Twelve 5X16 machine screws in the center area. Note the location of four large step-washers. These

mount the unit to the optional stand.

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FIGURE 5-1 - KDE61XBR950 SPEAKER HOUSING REMOVALPDP01.5-1 3/15/04

REMOVE FOUR4X16 SELF-TAP

SCREWS

PULL HOUSINGOFF

Speaker Housing RemovalRemove four 4X16 self-tap screws (marked by an arrow) for the left and right speaker housing as shown inFigure 5-1. Pull the housings off the panel.

Filter Glass Bracket RemovalThe filter glass bracket must be disassembled and removed from the rear in order to remove the plasma panel.Access to the mounting screws for the four large brackets can only be achieved if the filter glass bracket isremoved. These brackets and the circuit boards mounted to it must be separated from the old panel when a newone is being installed.Begin by removing the speaker wire connectors as illustrated in Figure 5-2. Peel back the conductive tape toaccess the connectors. Note the ground wire for each speaker connector. A 4X16 gold-colored self-tap screwsecures them. There are two of these screws one each side and four on the top and bottom. The filter glassbracket is secured to the panel by these and must be removed.

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LEFT SPEAKERCONNECTOR

RIGHT SPEAKERCONNECTOR

REMOVE GROUNDAND PEEL OFF TAPE

FIGURE 5-2 - SPEAKER WIRE REMOVALPDP01.5-2 3/15/04

82


FIGURE 5-3 - KDE61XBR950 FILTER GLASS BARS

REMOVE TWO 3X8 SELF-TAP SCREWS

REMOVE SIX 1.5X2 SELF-TAP SCREWS EACH BAR

PDP01.5-3 3/15/04

FIGURE 5-4 - LOOSENING THE PANEL BARS PDP01.5-4 3/15/04

PANEL IDLABLES

The four metal bars located around the perimeter of the panel are removed next. Remove the two black barsfrom each side. They are secured by two 3X8 machine screws each. This is illustrated in Figure 5-3.The long silver colored bars are removed next. They are secured by six 1.5X2 screws. This is also illustrated inFigure 5-3. Do not remove the screws at each end securing a small bracket. It is not necessary. Once theproper screws have been removed, strike the end of the bar with a leather or plastic mallet until it moves slightlyas shown in Figure 5-4. The bar is then pulled away from the panel assembly

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FIGURE 5-5 - ALIGNMENT SLOT FOR PANEL BARSPDP01.5-5 3/15/04

Once the bars have been removed from all four sides, the filter glass bracket can be lifted from the front filterglass. The plasma panel, along with the four brackets securing the circuit boards, is now resting on the front filterglass. The only thing keeping contaminants from entering the area between the plasma panel and the filter glassis the gaskets sealing the area. Do not lift the panel up unless you intend to replace it as cleaning of the surfaceswill need to be performed.NOTE: When re-installing the upper and lower bars, note that the lower bar contains the Sony name. The upperbar is blank. The bars also contain an alignment pin. The pin location is identified by a small dimple in the bar.This dimple is aligned with a slot in the clear plastic edge of the filter glass bracket before the bar is pressed intoplace. This is illustrated in Figure 5-5.

Panel Removal

If the panel must be removed for replacement, two people will be required due to the considerable weight of theplasma assembly. Figure 5-5 illustrates a panel where the filter glass bracket assembly has been removed.Once the panel has been separated from the front filter glass, the four metal brackets around the perimeter of the

84


FIGURE 5-6 - REAR FILTER GLASS BRACKET REMOVED

TOP AND BOTTOMBRACKETS SECUREDBY FOUR 4X16 SELF-TAP SCREWS EACH

SIDE BRACKETSSECURED BY TWO 3X16

MACHINE SCREWS

PDP01.5-6 3/15/04

panel must be removed. The top and bottom brackets are secured by four 4X16 gold-colored self tap screws atthe end of each cross brace. The side brackets are secured by two 3X16 machine screws at each end. Eachbracket contains a sealing gasket so use caution when removing them to avoid distorting or damaging thegaskets. Note the labels indicating the panel type and serial number along with the Vs and Vd voltages. Theseare viewed back in Figure 5-4.

DEM, K, G1 and G2 Board RemovalBefore the new panel can be installed, the boards listed above must be transferred to it. The replacement panelwill come with the Logic, High Voltage, Common and Address boards installed and aligned to the panel. Removethe following connectors from the indicated circuit boards:Remove the connectors from the DEM board as illustrated in Figure 5-7.

Remove two connectors and the temperature sensor from the High Voltage board as illustrated in Figure 5-8.

Remove the panel sensor as shown in Figure 5-9.

Undo any tape securing wires to the plasma panel. The cross-member brackets can now be disengaged fromthe panel by removing two 5X12 machine screws for each bracket as illustrated in Figure 5-10. The crossmembers are attached to sub-chassis frames holding the various circuit boards and can now be lifted from thepanel assembly. Use caution to avoid any unnecessary flexing of the assembly as it is being moved. The G2board is susceptible to the most strain.

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FIGURE 5-7 - DEM BOARD CONNECTORS PDP01.5-7 3/15/04

REMOVE CN3801,CN3303, AND CN3302

REMOVE WIRING FROMRETAINERS AND DRESS ASIDE.

FIGURE 5-8 - HIGH VOLTAGE BOARD CONNECTORS PDP01.5-8 3/15/04

REMOVE CN105 AND CN106REMOVE THERMAL SENSOR

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FIGURE 5-9 - PANEL THERMAL SENSOR

REMOVE THERMALSENSOR FROM PANEL

PDP01.5-9 3/15/04

FIGURE 5-10 - CROSS-MEMBER BRACKET PDP01.5-10 3/15/04

REMOVE TWO 5X12 MACHINE SCREWSFROM ALL FOUR CROSS MEMBERS

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FIGURE 5-11 - KDE61XBR950 PANEL BOARDS LOCATION

DATA RELAY(ADDRESS)

BOARDS

HIGH VOLTAGE(SCAN) BOARD

SCAN DRIVERBAORDS

PDP01.5-11 3/23/04

Scan, Address and High Voltage Boards LocationFigure 5-11 illustrates the location of the High Voltage, Scan Drive and Address Relay boards. Note the heatsinks that are unique to this model attached to the Scan Drive ICs.

Whenever the High Voltage board is replaced, four different voltages must be checked and re-adjusted asnecessary. These voltages vary from panel to panel. Many of the panels do not have a label defining thesevoltages although newer productions will. If the panel has such a label, it will be located on the rear of the panelabove the Common Relay board. It will define the following voltages, which can fall into theses specified ranges:

• VBW: 90 or 100VDC

• VP: 194 to 233VDC

• VSW: 160 or 170

• -VW: -60 to –79VDC

Note: If the panel does not have a label, the Technical Support line will need to be called. Provide the panel typeand serial number from the label at the top right corner of the panel and the proper voltages can be looked up ina database.

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Figure 5-12 illustrates the adjustment and test point locations for the voltages listed above. They are located onthe High Voltage Board.

FIGURE 5-12 - VOLTAGE ADJUST AND TEST POINTSPDP01.4-18 3/20/04

VBW ADJ ANDTEST POINT

VP ADJ ANDTEST POINT

VSW ADJ ANDTEST POINT

PDP010304 3/18/04

and i.LINK® are trademarks of Sony Electronics

©2004 Sony Electronics Inc.EMCS - A Service Company

1 Sony DrivePark Ridge, New Jersey 07656

Reproduction in whole or part without written permission is prohibited. All rights reserved

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