Today, I encountered an issue with a Sharp LCD model LCD-32NX155A. The indicator light was off and the screen wouldn't turn on. After disassembling the unit, I checked the fuse and found it intact. Then, I tested the large filter capacitor on the power board and saw that it had 320V, but the motherboard wasn't receiving any power. I disconnected the power board from the motherboard and checked for shorts. The power board didn't show any issues, but the motherboard had a short circuit.
After a thorough check of the power supply to ground on the motherboard, I removed three chip capacitors. One of them was shorted, which turned out to be the main problem. I couldn't find any other faulty components in the circuit. I used a similar chip capacitor (around 500nF) from another discarded board, and after replacing it, the power supply to the motherboard returned to 12.3V. The repair was successful.
Many parts in this unit don’t have standard numbers or sockets, making the repair a bit tricky. I came across a Taobao guide online that claimed the fix would cost only 30 yuan by replacing a small component. It seems like the same patch capacitor was involved. I’m sharing my experience here to help others who might face similar issues. Thanks for reading and supporting my work!
Power board number: QPWBFG316WJN2
Motherboard number: QPWBNG308WJN2
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