Pc (Analog) No Screen - Samsung P2770HD Service Manual

4-3. PC (ANALOG) No Screen

The LED power is on but no picture is displayed on the screen when the D-SUB cable is
-
Symptom
connected
Even though the LED power turns on, the screen is blank when connecting the VGA cable.
-
Check the D-sub cable connections.
Major -
checkpoints
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
Caution Make sure to disconnect the power before working on the IP board.
Does led persists green light after
power on?
Yes
Does proper 5V appear at pin No.
9 of CN8003?
Yes
Does proper V-sync ④ and H-sync
⑤ appear at C809 and C808?
Yes
Does proper clock signals appear
at pin NO.11,12,23,24 of CN1005?
Yes
Check connection between main
board and panel.
Change Panel.
CN1005
CN8003
Main Board Front
No
No
Check D-sub cable connection
No
No
because of scaler problem
4. Troubleshooting
Check IP board
Check PC state
Change main board
4-5