PANASONIC VIERA PLASMA DISPLAY FAULTS - FULL TROUBLESHOOT GUIDE

Plasma TV Troubleshooting - Panasonic Viera Plasma Display fault - troubleshoot -1

Panasonic Plasma TV - Troubleshooting - 1

HD Step Up Models TH-50PX500 - TH-42PX500 - TH-58PX600 - TH-50PX600 - TH-42PX600

HD Leader Models TH-50PX50 - TH-42PX50 - TH-37PX50 - TH-58PX60 - TH-50PX60 - TH-42PX60 - TH-37PX60 SD Leader Models TH-42PD50 - TH-42PD60 

* A short circuit on the voltage lines.
* Over-voltage condition.
* Abnormality in the Control Drive Pulse circuit i.e. SC, SS, SU or SD boards.
* Missing source voltage to the PA board (STB14V) from P board.
* Missing output voltage from the PA board to the DG board.
* Missing 15V or Vsus on either SS or SC board while the control drive pulses from the D board are being provided.

D Board SOS detect

DG Board SOS detect

PA Board Test Points

LED BLINKING 10 TIMES

When the power LED blinks 10 times right after the Plasma TV has been plugged in to the AC source, the possible defective boards are:

P Board
PA Board
DG Board
H Board
DT Board

How to Rule out the P Board

Use a Peak Hold Meter for voltage reading

NOTE: Follow this procedure when the click sound of the relay can be heard after the unit is plugged in. 

1. If the relay does not click, check the STB 5V from the P board. If the STB 5V is missing, the P board may be defective.  (If STB 5V is OK, the DG board may be defective.

2. Disconnect Connector P10 on the P board. (Make sure that the TV is unplugged)

3. Because you only have 2 – 3 seconds to measure the STB14V, place your meter’s probe at pin 1 of connector 10 of the P board before plugging the TV in to the AC line.

4. Plug the TV in to the AC line while still holding the probe at Pin 1.

5. Check to see if the 14V comes up. If it does not come up the P board is defective. If it does, (since it may take some involvement to determine which of the PA or DG board is defective) it is OK to order both the PA and DG board together.

To rule out H Board

1. Disconnect connector H40 then plug Plasma TV to AC line.
2. If the power LED stops blinking, the H board may be defective; otherwise another board is causing the problem.
NOTE: It is recommended that the PA board be replaced at the same time if the H board is suspected to be defective and will be replaced.

To rule out the DT (Digital Tuner) Board

1. Remove the DT board and then plug the Plasma TV into an AC source.
Note: When the DT board is removed, the unit will still power up but all functions are disabled due to the lack of data communication.
2. If the power LED stops blinking the DT may be defective otherwise, another board is causing the problem.
3. Other possible causes of blinking are the PA or DG board.

LED BLINKING 5 TIMES

This blinking code is caused by abnormalities in the 5V voltage supply line.
Other possible cause is a problem in Vda supply voltage line.

Other Cause of 5V SOS

The Power LED can also blink 5 times if the Vda voltage is shorted. This is normally

caused by the Panel demultiplexer ICs.

Procedure to properly isolate C Board

When the ribbon cables from the D board to the C boards are disconnected in order to isolate the C   boards, the LED will blink 6 times.

• To properly isolate the C boards to avoid 6 blinks, TP9387 (on the D board) should be grounded by a

1Kohm resistor.

Note: The next slide will show reasons why SOS 6 blinks is generated when the ribbon cables are removed.

• The Vda connector should also be disconnected.

Fan SOS

To determine if the fan is the cause of the 11 blinks, simply use a peak hold meter to determine if pin 3 of the fan connector goes high before shut-down.
• If it does, the fan is defective.
• If not, check the other fans and the fan drive circuitry.

No Video and No OSD

Determining whether a no video or no OSD symptom is caused by the video process or the panel drive circuit

Isolation of SC & SS Board

If any of the connectors providing the 15V or Vsus voltage to the SC or SS board is disconnected, while the connectors providing the scan and sustain drive pulses are present coming from the D board, the Plasma TV will shut-down.

Isolation of SC Board

SC2, SC23 & SC20 Disconnected:

In this condition, when the SC2 SC20 & SC23 are disconnected the SC board is completely isolated from sources (P and D board).

The power LED stays on and the panel is primed.

Expectations when isolating SC Board

The SC board could be isolated from the driver boards (SU&SD)

Sometimes the TV will go into Shut-down indicating that the problem is located on the SC Board. This does not necessarily mean that the SC board is the cause of the Problem.  When this occurs, disconnect both the SU and the SD boards from the SC board.

To disconnect, remove the 2 screws holding each of these boards in place and disconnect SC41, SU45, SD46 and SC42.

Sometimes the TV may not go into Shutdown, when there is a scan problem.  This symptom seems to be caused by a defective D or SC board.  When in reality, it is caused by the SU board.

When this occurs, disconnect the SU board from the SC board.  Disconnecting the SU board yields a good picture at the bottom half of the screen and a completely black area in the upper half of the screen.

Isolation of SU Board.

Screen-shot – defective SU

Isolation of SD Board

Click on the pictures to magnify

 

Panasonic Viera Plasma Display faults - troubleshoot P2

HD Step Up Models: TH-50PX500 - TH-42PX500 - TH-58PX600 - TH-50PX600 - TH-42PX600

HD Leader Models: TH-50PX50 - TH-42PX50 - TH-37PX50 - TH-58PX60 - TH-50PX60 - TH-42PX60 - TH-37PX60

SD Leader Models: TH-42PD50 - TH-42PD60 

Common Problems

Symptom: Dead/LED off (no blinking code).
Cause: Vsus (Sustain voltage) voltage line shorted to ground due tco shorted transistors.
Remedy: Replace Q6611, Q6612, Q6613, Q6613, D6609, open R6710 & R6708.  After replacement, check that Vsus line is no longer shorted to ground.

Symptom: Picture pixelized @ area horizontally across the screen.
Cause: Initialization pulse T2’s level settings is misadjusted.
Remedy: Adjust VR6557 to obtain specified level settings (T2=184 µsec).

Symptom: Blue vertical line @ right most edge of the screen.
Cause: Missing data line.
Remedy: Open R7125

Symptom: After pressing power button, unit shutdown then LED blinks 7X Cause: SOS protection circuitry detects problem in scan output waveform Vf due to shorted scan output transistor Q6511.
Remedy: Replace both Q6511 and Q6512 at the same time.

Symptom: Distorted picture.
Cause: Missing TPVSET voltage due to open R6602 & shorted C6526
Remedy: Replace R6602 & C6526.

Symptom: After pressing power button, unit shutdown then LED blinks 7X
Cause: SOS protection circuitry detects problem in scan output waveform Vf due to shorted scan output transistor Q6511.
Remedy: Replace both Q6511 and Q6512 at the same time.

Symptom: Dead/relay will not click & LED remains off (no blinking code).
Cause: No output from power output control module.
Remedy: Replace MC701

Symptom: Dead/relay will not click & LED remains off (no blinking code).
Cause: No standby voltage.
Remedy: Replace IC501.

Symptom: After pressing power button, unit shuts down then LED blinks 7X

Cause: SOS protection circuitry detects problem in scan output waveform Vf due to shorted scan output transistor Q6604 & Q6654.

Remedy: Replace Q6604 and Q6654.

Symptom: Upon power ON, relay clicks then LED blinks 8X.
Cause: No sustain pulse output waveform due to shorted D6020 and/or D6021.
Remedy: Replace both: D6020 & D6021 at the same time.

Symptom: Dead/relay will not click & LED remains off (no blinking code).
Cause: No primary supply to T501 thereby no secondary voltage outputs.  Due to open in-rush current limiter K601 & open RF601.
Remedy: Replace K601 & RF601.

Symptom: Upon power ON, relay clicks then LED blinks 10X.
Cause: No switching voltage output from F14_ON or 12V/15V_ON pins.
Remedy: Replace power module MC501.

Symptom: Very intermittently unit shutdown and LED blinks 7X.
Cause: No solder @ pin 4 of IC6773.
Remedy: Resolder pin 4 of IC6773

Symptom: Shuts down with power LED blinking 10x.

Cause: Missing 395Vdc output due to shorted Q412 & Q413.
Remedy: Replace Q412, Q413, Q408, Q409, R478 & PR401 on the P board.

Symptom: Dead/power LED off (no blinking code).
Cause: No primary AC voltage inputs due to open fuses caused by Q406 shorting out.
Remedy: Replace F401, F402, Q406 & check/replace thermal resistor (R410) on the P board.

Symptom: Picture disappears after few minutes but sound is OK.
Cause: Low Ldo_5V supply to IC9800 (DC to DC Converter) due to leaky D9801.
Remedy: Replace D9801 on the D board.

Symptom: Shuts down with power LED 10 blinks.
Cause: Missing 395Vdc output due to shorted Q412 & Q413.
Remedy: Replace Q412, Q413, Q408, Q409 & PR401 on the P board.

Symptom: Dead/power LED off (no blinking code).

Cause: No primary AC voltage inputs due to open fuses caused by Q406 shorting out.

Remedy: Replace F401, F402, Q406 & check/replace thermal resistor (R410) on the P board.

Differences 2005: 50PX500/PX50 2006: 50PX600/PX60

1. The PB and Z board are now on the PA Board

2. Location of the PA and D board was changed

3. HDMI interface (DV) relocated.

4. HC board added （factory use)

Differences 2005: 42/37/PX500/PX50/PD50 2006: 42/37/PX600/PX60/PD60

1. The PB and Z board are now on the PA Board

2. Location of the PA and D board was changed

3. HDMI interface (DV) relocated.

4. HC board added （ factory use)

5. Reduce the upper C boards for single scan.

6. Reduce the S2 and S3 boards.