ln46a550p3fxza picture issues, squealing board

[sidneyaks]

So I got one of these from a friend of the family. They had been kicking it around for a while (according to the wife, it went bad in warranty, but they were too lazy to take it back, wish I could afford that!). When turned on there are very dark vertical lines (note: not black, just very very dark in relation to the rest of the tv), with red tinted borders.

I took off the back and there doesn't appear to be any bulging caps on the power board. I was sitting with it on for a while, and eventually the picture snapped to full brightness across. Upon further inspection from the back, the TCON board is squealing quite loudly.

It appears as though the squealing is coming from the side of the board that corresponds to the side of the TV with the issues. I can't pinpoint the sound with my ear, but when I touch the board on the side with the issues the tone changes substantially. No tone change on the other side.

Pictures attached. The first one is what the screen is doing, the other two are connectors. I'd like to get them open to try cleaning them, but I can't figure out how. Pointers would be nice?

[budm]

Re: ln46a550p3fxza picture issues, squealing board

The squealing is more likely to be coming from small black round inductor, about 1/2" round, which is the switching power supply, this is due to too much current is is being pulled by bad ICs on the flexible cable for driving the TFT on the LCD panel. You can disconect one of the flat brown cable to see which one will stop the squealing. At this point I would say you have bad LCD panel, similar to this squealing I get form my T-CON board, see post 10
https://www.badcaps.net/forum/showth...ight=LG+47LH55