LG 50PG20- No Picture. just humming noise

[bekweezee]

Im very new to electrial type work but Im quick at learning and want to fix this myself.

I was watching TV today and a "pop" noise happend and the screen went black.

I did some research and tore the TV apart. A visual inspection of the boards looked good.

I decided to take the wire harness off of the Y-SUS board and then plug the TV in and turn it on. The humming noise was not present. I plugged the harness tothe Y board back in and then turned the TV on again and the humming was there.

I got a multimeter and there were 5V going into the y-sus board.

On the thinner Y-boards on the left, I looked and seem that +5v was supposed to power the 7/8 slot [see picture] but no power was present.

Is it an accurate assessment to say the problem is in the YSUS board?

Thank you in advance for your assistance:







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[bekweezee]

Re: LG 50PG20- No Picture. just humming noise

please help

[capkid]

Re: LG 50PG20- No Picture. just humming noise

It sounds like a Y-Sustain problem:
- Have you closely examined the board for burns or visibly damaged components?
- Are there any blown fuses on the Y-Sus? Check the fuse(s) on the Z-Sus, also. Fuses are usually marked with an "F" prefix.
- Is there an LED on the Y-Sus, and is it lit when the TV's turned on?

I don't know this chassis very well, so I'm unsure of what's under the heat sinks. Can you post a pic or two of the heat sinks from a different angle?

[tom66]

Re: LG 50PG20- No Picture. just humming noise

Also, carefully check the panel for cracks. A loud buzzing can be due to a cracked panel, and the crack can be very small.