- THERE ARE TWO KINDS OF PICTURE PROBLEMS TO PLASMA DISPLAYS.
- Abnormal picture.
- No picture.
- BASIC CONCEPT OF DETERMINING THE DEFECTIVE BOARD
- 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 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."
