Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or repair the product or products dealt with in this service information by anyone else could result in serious injury or death.
How to determine the defective board.
Verification of voltages
Normally, when there is a power problem, shutdown occurs immediately. So, to resolve a power problem, voltage checks are necessary before shutdown.
Check if the power comes up after disconnecting the suspected board. If power comes up after disconnecting a board, the board is defective. “Power comes up” equals “no shutdown”.
After exchanging the following boards, voltage adjustment is required.
P board, SC board, SS board,
Defective Board - A Board.
To confirm this, unplug the TV and disconnect connectors A5, A6, and A7 from the A board.
The TV should turn on automatically and display a white screen.
Warning: Disconnect AC Power prior to making any disconnection or connection.
Defective Board (Possibility)- P, D, A, SC, SS Board (P > A, D, SC, SS)
[Always Disconnect AC Power prior to making any disconnection or connection.]
(*1) = The reference number of the sustain data connector is different in some of the models:
TH-42PX75U = SS23
TH-42PX77U = SS23
TH-50PX75U = SS33
TH-50PX77U = SS33
Defective Board-D Board: Trouble Mode-3.3V down SOS
LED Blinking codes detail
LED blinks 4 times
Defective Board-Primarily P board or possible D board: Trouble Mode-Power Supply SOS
Turn the unit on. Is pin 12 of CN P25 of the P board high before shutdown?
If no, D board is defective.
If yes, P board is defective.
LED blinks 5 times (Quick Troubleshooting)
Defective Board-D, P, C, SC, SS board or Panel (DDIC)*1: Trouble Mode-5V SOS
(*1) = Data Driver IC
LED blinks 5 times
LED blinks 5 times-D, P, C, SC, SS board or Panel: Trouble Mode-5V SOS
How to find defective board.
LED blinks 6 times- Defective Board (Possibility)- SC, SS, D, P Board (SC > SS, D, P )
Trouble Mode-SC Energy Recovery SOS
How to find defective board.
LED blinks 6 times-Defective Board (Possibility)- SC, SS, D, P Board (SC > SS, D, P ): Trouble Mode-SC Energy Recovery SOS
LED blinks 7 times-Defective Board (possibility): Trouble Mode-SC Floating voltage SOS
How to find the defective board.
LED blinks 8 times-Defective Board (possibility): SS, SC, D, P board (SS>SC,D,P)/PDP: Trouble Mode-SS Energy recovery SOS/Panel
LED blinks 10 times before pressing the power button-Defective Board-P, A Board: Trouble Mode-SUB 5V SOS, Main 3.3V SOS DTV 9V SOS, Tuner Power SOS
How to find the defective board.
LED blinks 12 times-Defective Board (Possibility)- Speakers, A Board: Trouble Mode-Sound SOS
No Power/Dead Unit-troubleshooting
No Picture from one or all inputs (OSD and Sound OK)- All models
No Picture / No OSD-All Models
No Sound
There are two kinds of picture problem. 1) Abnormal picture. 2) No picture.
Basic concept of determining the defective board.
1) Which area is the symptom displayed on the screen?
A. Part of the screen
B. All over the screen
Adjustment after PCB exchange.
After exchanging the following boards, voltage adjustment is required. P board, SC board, SS board.
Diagnosis by Test Pattern When OSD is Available.
Picture problem such as “Picture Noise and or Vertical Line” displayed all over the screen is mainly caused by a defective D or A board. The “internal Test Pattern Generator” can help determine whether to replace the D or A board. The test patterns are created by the D board. Follow the steps below to confirm the operation of the D or A boards.
Diagnosis by Removing the A5 Connector.
Symptom such as “No picture, No OSD, Sound OK” is mainly caused by a defective A or D board. The internal pattern generator cannot be accessed due to the loss of OSD. This method makes it possible to determine whether the A board or the D (SC,SS) is defective.
Troubleshooting for Picture Trouble. How to determine the defective board.
Diagnosis for Picture Problem (All Over the Screen). Abnormal Color, Vertical Line, Sync Error, Noise Picture-All Models
Diagnosis for Picture Problem (All Over the Screen).
Enter the “Internal Test Pattern Generator”
or
Is the screen “White”, after disconnecting the connector “A5”?
Vertical Line Problem.
Picture Trouble at Upper or Lower half.
Picture Trouble at Right or Left half (50 Inch)
Picture Trouble at Right or Left half (42 Inch).
Picture Trouble in 50 Inch Models. No Picture, Picture noise, Half Vertical line, etc.
Picture Trouble all Over the Screen. Picture noise, Full Vertical line, etc.
Symptoms and Remedies.
Picture Problem (All over the screen). Noise Picture, Vertical Line.
Abnormal colour and sync error.
Picture Problem (Right half or Left half).
Self-check Procedure. CHASSIS: GPH10D: All models.
[This procedure does not reset the TV]
How to access the self-check screen to reset the unit.
Select a television channel, and while pressing the [VOLUME ( - )] button on the main unit, press the [OK] button on the remote control for more than 3 seconds.
How to Exit the self-check screen.
Press and hold the Power button on the TV for 5 seconds or disconnect the AC cord from the wall outlet.
TV volume down & OK on remote only does a basic IC self check. It does NOT Reset the TV.
It does not clear channel programmed settings, picture settings, channel labels, LOCK mode settings, or password.
Using this method, it shows the unit firmware version (Peaks 1.050 and GenX 1.00) and it checks IC communications ONLY.
This is more useful to identify the firmware version without having to decode the info in the setup menu About/Version screen.
To Reset the Unit, turn the TV on and while pressing the “VOLUME ( - )” button on the main unit, press the “Menu” button on the remote control for more than 3 seconds.
The Self-Check menu appears on screen. Then, disconnect the AC cord from the wall outlet.
[Note: All customer programmed parameters will be erased.]
TH-42PX75U/ TH-42PX77U Driver Setup Adjustment.
1. Input a white signal to plasma video input.
2. Set the picture controls as follows.
Picture menu: Vivid
Normal: Set
Aspect: Full.
Caution
1. First perform Vsus adjustment.
2. Confirm the voltage level of VSCN. This should be done after the adjustment of Vad which should be - 105V
When Vad = -105V, Vscn voltage is 40V ±4V.
Initialization Pulse Adjustment.
1. Input a 100% White signal to the unit.
2. Set the picture controls as follows:
Picture menu : Vivid
Normal : Set
Aspect : Full
3. Connect an Oscilloscope to test point TPSC1. Using VR6602, adjust (T2) for 195+/-10ยต Sec.
TH-50PX75U - TH-50PX77U Driver Setup Adjustment.
TH-42PX75U and TH-50PX75U BOARD LAYOUT AND PART NUMBERS
TH-42PX77U and TH-50PX77U BOARD LAYOUT AND PART NUMBERS
