Samsung S19A100N

4-4
4. Troubleshooting
4-3. When the screen is blank
Symptom Even though the LED power turns on, the screen is blank when connecting the VGA cable. -
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 Main board. -
Diagnostics
CN400
IC601
X401
R107 ~ R112
CN600
IC400
Yes
Yes
Check and replace the circuits
related to X401.
No
1 Is X401 oscillating correctly?
Check the signal cables and their
connections.
Do the RGB inputs appear at
R107~R112?
Check the R107~R112 input
terminals.
No
Yes
Check the circuits related to
IC400.
Check the circuits related to
CN400.
Check the +5V_Panel signal
and the BL_EN signal.
No
No
No
Do the 2 Hsync and 3 Vsync
waveforms appear at pins 38, 39 of
IC400, respectively?
Yes
Yes
Yes
Do output signals appear at pins 13,14,
16,17,19,20,22,23,25,26 of CN400?
Is DC 5V measured at pins 1 ~ 5
of the CN400?
Check and replace the panel.
Caution Make sure to disconnect the power before working on the Main board.