Samsung LN40B540P8FXZA damaged tab bonding

[budm]

I just open this one up today and was hoping for poor bad tab bonding repair (from the pictures that I can see when I turn it on), as it turns out, it has badly damaged tab bonding due to liquid spilled into the panel, since the tab bondings are at the bottom of screen, the damage is beyond repair, about 10 or more traces were gone due to corrosion.

[retiredcaps]

Re: Samsung LN40B540P8FXZA damaged tab bonding

Those excellent pictures of the corrosion. Thanks for the teardown.

[netdent]

Re: Samsung LN40B540P8FXZA damaged tab bonding

Have a samsung with the same insides, also tabs at the bottom, no spillage but similar problem, trouble is somebody was at it before me while I was working on it stripped down as you have done I noticed one of the tabs was getting very hot! it caught fire! that was the end of that!

Ronnie

[randtek]

Re: Samsung LN40B540P8FXZA damaged tab bonding

It is generally a REALLY BAD idea to operate one of these panels for more than a few seconds without the metal frame installed. the frame act as a heat sink for those ICs on the flex tabs. Once the heat starts in one of those ICs, it will very quickly accelerate due to thermal runaway. Then the panel is toast. I have seen one fry in as short as 30 seconds.

[tom66]

Re: Samsung LN40B540P8FXZA damaged tab bonding

That is also very true for plasma display panels. A user on here fried an almost working 50" plasma TV by removing the address buffer heatsink. Lots of stuck vertical lines and dead bars now. That was less than a few minutes, I believe.

And I had a 32" with bottom mounted tabs have one of the tabs catch fire. But that was with the frame on. I guess it's just a common defect, especially common as those drive ICs make a significant portion of the cost of the LCM (liquid crystal module), and cost cutting always comes into play.