Samsung S22A350H - 4-4. When a blank screen is displayed (HDMI)

4-7
4. Troubleshooting
4-4. When a blank screen is displayed (HDMI)
Symptom - Even though the LED power turns on, the screen is blank when connecting the HDMI cable.
Major checkpoints
- Check the HDMI 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 Mainboard.
Diagnostics
CN400
X401
IC400
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 R300
to R307?
Check the R300 to R307
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 Main board.