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 D board creates the test patterns. Follow the steps below to confirm the operation of the D or A boards.
Pattern = Abnormal
D Board
Pattern = Normal
A Board (or D board)
TO ENTER THE TEST PATTERN
- While pressing "VOLUME-" button of the TV set, press "RECALL" button of the remote control three times within 3 seconds.
- Push button"1" of the Remote Control several times to select the “AGING" setting.
- Press the number “3" button or the number “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 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.
Diagnosis
Connect the TV after removing A5 Connector
Symptom
No picture (Sound OK)
White Picture = A Board (D board)
No Picture = D board (SC or SS)
BLOCK DIAGRAM & EXPLANATION
- This white pattern is generated by IC9900 on D board.
- When the TV is plugged in after disconnecting connectorA5, it turns on automatically and a white picture is provided to the panel drive circuit. If the panel drive section of the unit is ok, a white picture is automatically displayed by the PDP.
HOW TO DETERMINE THE DEFECTIVE BOARD
PANEL GAS LEAKAGE
Because of a very small crack in the panel, gas leakage will
start. In this picture, gas leakage
started at the left top corner. Finally,
gas leakage will lead to the symptom “No picture with buzz noise”
Abnormal Color, Vertical Line, Sync Error, Noise Picture
[For all models]
- A Board, D Board, SC Board, SU Board, SD Board
- Enter the “Internal Test Pattern Generator”
- Is the screen “White”, after disconnecting the connector “A5”?
- Test Pattern OK or White Picture displayed
- Test Pattern NG or White Picture not displayed.
