Samsung SyncMaster EX2220, Service Manual

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4-7
4. Troubleshooting
4-4. When a blank screen is displayed (Digital)
Symptom - Even though the LED power turns on, the screen is blank when connecting the DVI cable.
Major checkpoints
- Even though the LED power turns on, the screen is blank when connecting the DVI cable.
- Check the DVI 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.
Diagnostics
CN400
IC400 X401
R109, R110, R113
Yes
Check the signal cables and
their connections.
Yes
Check and replace the circuits
related to X401.
No
①
Is X401 oscillating correctly?
②
Do the inputs appear at R206,
R210, and R213?
Check the R206, R210, and
R213 input terminals.
No
Yes
Do output signals appear at pins 8 to 30
of CN400?
Check the circuits related to
CN400.
No
Yes
Can DC 5V be measured at pins 1, 2,
and 3 of CN400?
Check the Panel EN signal
and the BL_EN signal.
No
Yes
Check and replace the panel.
Caution Make sure to disconnect the power before working on the IP board.