Samsung SyncMaster 320TSn-2, Service Manual

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4-4
4. Troubleshooting
4-3. No PC(D-SUB) Video
Symptom Though the LED power turns on, the screen is blank when connecting the VGA cable.
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Major
checkpoints
Check the D-sub cable connections.
Check whether the LVDS cable is connected correctly to the panel.
Check whether the lamp connector of the panel is connected correctly to the IP board.
Check the circuit related PC input and scaler operation.
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-
-
-
Diagnostics
CN401
C603
IC302
CN101
YES
Check the power port.
No Does the LED light up when turn on
the power?
Does 5V appear at Pin 10 of CN101
D-Sub?
Check the cable connection.
No
YES
Does the waveform as the figure at Pin
17 ( H-sync)
⑤
and Pin 8 (V-sync)
⑥
of IC302 appear?
Replace IC102.
No
YES
Is TX** signal sent to Pin 16 and 17 of
CN401?
The Scaler(IC302) is
abnormal. Replace the main
board
No
YES
Check the cable between the main
board and panel and replace the LCD
panel.
Caution Make sure to disconnect the power before working on the IP board.