Re: Samsung 23" LCD P2350 Inverter Repair

Monitor fixed. Turns out Diode "D203" (5V rail secondary rectifier diode) was conducting in both directions.

The inverter chip was going into burst mode due to either overload protection or overvoltage feedback due to there being no 5V rail.

Re: Samsung 23" LCD P2350 Inverter Repair

I also have the same inverter board, I think someone did a 500V insulation resistance test on the screen an blew it up.

I have tested all fuses. There is 13V on Pin 2, but nothing on the 5V pin 5/6 or the 3.3V pin.

I put the scope across Drain and GND of the SMPS IC (U101) and am only getting switching bursts 500ms apart. I assume this is the low power mode of the chip. Should the chip be in standby mode or is there something wrong here?