LG 47v550t possible panel failure?

[Klinux]

I salvage this 47" LED LG LV550T it was displaying black and white lines my initial thought was tab bonding issues or connector ribbons to the tcon and panel.
I fired it up quickly and noticed that in one of the strips the tv menu was displayed but polarised and backward. I left the set on about to do some checks cables seated properly etc looked back at the screen and noticed the picture completely gone, backlight still on but nothing no lines.

Tcon chip was ridiculously hot so assuming it had failed I ordered a new tcon which I got for pennies I've installed the tcon and I'm back to where I was with the lines the only difference is the part polarised image comes and goes its still backward.

There's no real reaction to tapping the screen

Any advice is much appreciated I'm gonna check out the voltages here's some pics

[tom66]

Re: LG 47v550t possible panel failure?

I'd check the panel tab bonds - if one is getting hot it may be defective.

[Klinux]

Re: LG 47v550t possible panel failure?

I'm gonna strip the bezel off and check the tab bonds, what threw me was the fact that the part image of the tv menu and the no signal LG logo was backward.

[tom66]

Re: LG 47v550t possible panel failure?

Strangely, bad tab bonds have been found to cause inverted images, I am not sure how but they can.

[budm]

Re: LG 47v550t possible panel failure?

Yep, I found that inverted image (partial screen) problem on 26" SAMSUNG with bad tab bonding.

[Klinux]

Re: LG 47v550t possible panel failure?

Ok bezel off and tabs exposed.....hmmm its quite clear from looking firstly at the metal surround scorching looking closer at the tabs a couple of the tabs have actually burnt out on some of the lines, looking at it there is staining on the metal surrounds which could be liquid or resin residue from the melted parts of the tabs, possibly gotten in there. Bottom line major panel failure, a real shame it's a nice 3d smart TV. But hey it was free and adds a bit to the knowledge will salvage some boards and scrap the panel.