Another possible way to fix a tab bond issue.

[Dang]

To be treated as just another way to potentially fix the tab bond error.

I have a Sony KDL-40V3000 with the dreaded tab bond issue, I have spent a number of hours over about 6 or so occasions taking it apart and doing my best to try and resolve it, I now think I've finally sussed it, fingers crossed. So it's in the usual spot, that being the top far left tab, I've tried applying pressure with thermal pads where it connects directly to the LCD screen, I've tried applying pressure with the same material to where the tabs are bonded to the driver boards, I've also tried applying pressure to the small ICs bonded to the tabs, all worked to varying degrees but never actually cured it so this time I've tried something a little different as a last ditch attempt and it seems to be doing the job. Yet again, using the thermal pads, I've unscrewed the driver board at the offending end and raised it about 2mm to 3mm using a slither of the thermal material just where the tab just starts to loop over to LCD panel and then another of about the same thickness and size on the opposing side, the driver board has then been carefully screwed back down. So far it's been fine, it's been about a week and every time it's started from cold it's been without issue. Only time will tell if it's completely resolved the issue but so far it's certainly the best it's ever been, I hope this may of been some help to people.

[budm]

Re: Another possible way to fix a tab bond issue.

I have been lucky with two I repaired last week, they are still running.
https://www.badcaps.net/forum/showthread.php?t=37887
https://www.badcaps.net/forum/showthread.php?t=37885
The SONY and the SAMSUNG I repaired in late 2012 are still running great.

[tom66]

Re: Another possible way to fix a tab bond issue.

One of the ideas I've had about tab bond repair is to try a "heating" repair on them. I have a 32" Samsung panel (old, 2005 era) with an intermittent single line that disappears upon pressing the tab, but I can't get any shim to work.

I found that it was mainly dependent on the chip on the bond being pressed. I've got a heat gun, I'm thinking of trying to reflow the chip directly on the tab. I'd need to protect the LCD while I do this of course. But it's worth a shot, I think. I've another panel to replace it with anyway, if it doesn't work.

[Dang]

Re: Another possible way to fix a tab bond issue.

Interesting, I've had good success using a similar method to yours before now but this one, as stated above, has proved a lot more difficult. I have fixed a plasma before now that was suffering from coloured vertical lines, this was solved by anchoring the PCBs that were attached to tabs a little further down thus pulling the tabs "flatter" and enabling them to make contact again, this was done with shims made from old credit cards; so I applied this simple idea but by using thermal pads and it seems fine, hopefully for the life of the Tv fingers crossed.

[tom66]

Re: Another possible way to fix a tab bond issue.

Dang, that is the first time I have ever heard of anyone fixing a tab bond issue on a plasma. I was more or less sure it didn't exist due to how well heatsunk the address drivers are (although this is less true on modern panels.)

[Dang]

Re: Another possible way to fix a tab bond issue.

Dang, that is the first time I have ever heard of anyone fixing a tab bond issue on a plasma. I was more or less sure it didn't exist due to how well heatsunk the address drivers are (although this is less true on modern panels.)

I wish I had pictures to show you, but if I can explain in simplistic terms as I have very little proper terminology: you have the screen(upright), across the bottom are about 8 ribbons, these are terminated with PCBs(each supported with a metal bracket) which are then folded back 90 degrees and then anchored to the supporting metal frame, each bracket using two screws, one at each end. It's here that I used the credit cards to force down the PCB/bracket at one end and so extending out(flattening) the ribbon and curing the fault(been 3 months), it worked here and similarly seems to be working with the Sony, at least I'm hoping.

[tom66]

Re: Another possible way to fix a tab bond issue.

Yeah, I know how the drivers work. It's interesting because I have heard of intermittent issues on some plasma panels, intermittent vertical bars etc. However it is usually due to a loose connection because the IC is generally encapsulated in the bond, unable to move. Tab bond issues "can't" happen -- well, obviously they can on the newer panels which have changed the design quite a bit.