Samsung LEF22VS, 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
- Check the DVI cable connections.
- Check whether the LVDS(FFC) cable is connected correctly to the panel.
- Check whether the lamp connector of the panel is connected correctly to the Inverter.
Diagnostics
CN601
CN400
X201
IC101
IC200
CN700
Yes
Check and replace the circuits
related to X201.
No
①
Is X201 oscillating correctly?
②
Do the RGB inputs appear at R100
to R105 of CN102?
Check the R100 to 105 input
terminals.
No
Yes
Do output signals appear at pins 8 to 30
of CN400?
Check the circuits related to
CN400.
No
Yes
Is DC 5V measured at pins 1, 2 and 3
of CN400?
Check the +5V_PANEL signal
and the BL_EN signal.
No
Yes
Are IC101 inputs/ outputs and signals
correctly inputted and outputted?
Check the signal cables and
their connections.
Yes
Yes
Check and replace the Panel.
Check the circuits related to
IC101.
No
Caution Make sure to disconnect the power before working on the Adaptor.