PLASMA DISPLAYS TROUBLESHOOTING
- THERE ARE TWO KINDS OF PICTURE PROBLEMS TO PLASMA DISPLAYS.
- Abnormal picture.
- No picture.
- BASIC CONCEPT OF DETERMINING THE DEFECTIVE BOARD
ADJUSTMENT AFTER PCB EXCHANGE
After exchanging the following boards, voltage adjustments are required.
P' board,
'SC' board,
'SS' board,
FAULT FINDING BY TEST PATTERN; WHEN [OSD] IS AVAILABLE.
- Picture problems such as picture noise and or vertical line displayed all over the screen is mainly caused by a defectvie [D] or [A] board. The Initial Test Pattern Generator can help to determine whether to replace the [D] or [A] board. These Test Patterns are created by the [D] board.
- Follow the steps below to confirm the operation of the [A] or [D] boards.
FOR ALL MODELS OF PLASMA DISPLAY
- Noise in picture: full vertical line.
Pattern => defective board.
Abnormal => [D] board.
Normal => [A] board or [D] board.
TO ENTER THE TEST PATTERN
- While pressing [Volume-ve] button of the TV set, press [recall] button of the remote; within 3 seconds.
- Push button [1] of the remote control several times to select the [Aging] setting.
- Press number [3] button or [4] button of the remote control to select the test pattern.
DIAGNOSIS BY REMOVING THE [A5] CONNECTOR.
Symptom such as [No Picture, No OSD, Sound OK] is mainly caused by a
defective [D] or [A] board. The internal test pattern generator cannot
be accessed due to the loss of OSD. This method takes it possible to
determine whether the [A] board or [D] [SC,SS] is defective.
- Connect the TV after removing [A5] connector. White picture? [A] or [D] board.
- No picture? [D] board, [SC] board or [SS] board.
- The white pattern is generated by IC9900 on the [D] board.
- When the TV is plugged in after disconnecting connector [A5], it turns on automatically and a white picture is provided to the panel drive circuit.
- If the pattern drive section of this unit is OK, a white picture is automatically displayed by the plasma display.
TO DETERMINE THE DEFECTIVE BOARD
- START.
- WHERE IS THE SYMPTOM DISPLAYED?
- UPPER OR LOWER HALF?
- Upper half? => SU board, or [D or SC boards]
- Lower half? => SD board or [D or SC boards]
- Both area? => SS Board or [D] board.
LEFT OR RIGHT HALF
- Right half? => D board or [C1 or Panel]
- Left half? => D board or [C2 or panel]
ALL OVER THE SCREEN
- Internal generator pattern is normally displayed?
- If yes; A board or D board.
- If no; D board, SC board or Panel.
PANEL GAS LEAKAGE
- Because of very small crack in the panel, gas leakage will start. We can see its symptom at the area where the gas has leaked, by showing a patched view on the portion. Usually seen at the corners of the display panel. Finally, gas leakage will lead to "No picture with Buzz noise."
- Which area is the symptom displayed on the screen.
- [A] Part of the screen.
- [B] All over the screen.
