Symptom, no backlight, but the LCD it self is OK.
Inverter board (left) and main board (right).
Inverter board close up.
From my observation, this board will works when hot but not when cold.
A lot of try and error to trace this but finally, found the culprit.
This cap value determine the 5001C PWM controller short circuit protection timing. As mentioned in the 5001C PWM controller datasheet, the timing must be much longer (generally 10 to 15 times) than the converter start-up period or the converter will not start.
Replace with Aluminum caps for testing...
Put it back in...
There you go :-)