Help Panny tc 55gt31 blinking led

[Stal8080]

Hello All,

I'm new here and aware there have been several issues in regards to the Panasonic Plasma and the blinking red light. Little back story....the other while watching it heard a faint popping sound and then tv went dark, followed by the infamous 7 LED blinks. Based off MY misunderstanding of trouble shooting steps and some misleading posts, I preceded removing the SC (5335BA) board and checking for shorts on that board. I had some of our engineers at work check for shorts on it and we found some on the transistors. So ordered the appropriate kit from shopjimmy and had them solder on the replacements parts ( I suck at soldering small parts). Powered TV back up and picture returned and everything look perfect.....for about 10 minutes and then the dreaded POP sound once again, this time the Q403 transistors blew and broke apart to some extent and back come the 7 blinks.

In retro spec, I obviously should have followed the trouble shooting guide, however I see a few referenced and a few videos on it but don't have a clear direction for my TV (so any help in that regard would be great).

With that, the current situation is this. I removed the SC board again and powered up the tv. Now I get 8 blinks which could point to the SS board???

This is where I'm at and honestly, I'm not sure where to go from here. I would appreciate guidance and help. Thanks again.

[tw2005]

Re: Help Panny tc 55gt31 blinking led

Sounds like a failed rebuild attempt. The 8 blink with SC removed is a red herring as that is the result expected.

make sure you check the buffer boards for shorts as well.

I had a crack at a 5335 board with only 3 parts shorted, took a chance replacing just those and it ran but lasted maybe an hour one night then the next night blew soon after turning it on.

Back to the drawing board, I'm blaming the fact I did not replace the entire banks of IGBTs in the shorted section. Waiting for parts to arrive.

I have another 5335 board in a ST30, and I just replaced 2 banks of 3 IGBTs, 30F131,RJP30H2 with a substitute and it's running fine.

Both TVs strangely though the SS boards had a shorted RCJ330N25 FET, Q002 I think. Found this after the SC was fixed and that gave 8 blink.

The other thing is the driver ICs , it's probably best practice to replace those in the sections damaged.

I'm still learning with these boards too but plenty of others have had a go, some good, some bad with varying amounts of parts needed. Those kits won't always cover every possible scenario.

I have a U30 which just needed 4 30F131 replaced and it's been fine for over a year now. Different board design but similar

[Stal8080]

Re: Help Panny tc 55gt31 blinking led

First off thanks so much for the help. Really appreciate it. Few items for clarity sake.

The other thing is the driver ICs , it's probably best practice to replace those in the sections damaged.

Which board are you referring to here---The SC board??

So basically I should start over on the SC board === order another kit from SJ?

IN Addition to that check SU and SD have not shorted out?

[Alastair E]

Re: Help Panny tc 55gt31 blinking led

Yes--He means all the tiny driver chips on the SC board that are/were involved with Any/All IGBT's that went short/blew, plus more probably--now a Failed repair done.....

In addition (If the same numbering sequence applies to these, similar to TNPA5081, 5105) if Q661 went short-- Q701, Q702, IC773, Q818, D702 and possibly IC771 and IC724....

Possibly IC521, and IC501 and the dual transistor driver pairs off each of these two chips, and maybe a diode or two as well...

As I said--These SC are not for feint-hearted! IF you don't get 'em all first time around--Then not only will it self-destruct again--but a whole load more silicon will be dead....
Most of the above are small/Tiny SMD devices and skill/equipment is needed to change without damage to parts Or more importantly--The Board itself.

Once tracks on the board are damaged--Thats the end of it in some cases....

These so-called 'repair-kits' are very often very lean on the parts needed to effectively repair any Pan. SC board--Miss one part that's faulty/dead, All your work (And cost) gone in about a tenth of a second....Check the comments boxes on Youtube for 'em....

Worth reading through the threads on TNPA5081 Rebuild and TNPA5105 --Although a different board, a lot of the same will probably apply, as same maker, will give you some general grounding in these SC boards....

[Stal8080]

Re: Help Panny tc 55gt31 blinking led

Thanks all.....need some advice again here:

Removed and Tested the SU/SD for shorts and everything checked out good.

So not sure where to go to here. All problems point to perhaps the SC board. Like previous posts when I installed the kit from SJ on the SC board I got the TV back, perfect picture for about 10 minutes before something on the SC board blew again. At this point, all I can think of is to buy a new kit but I'm sure that will result in same result. Is there a recommended forum member or site where I can send my board for repair?

Or I'm confident if a had a complete list of parts to check/test and parts to buy we have the right equipment at work to make repairs. In addition considering purchasing a new SS just to be safe----any thoughts?

[Stal8080]

Re: Help Panny tc 55gt31 blinking led

Ok Decided to send SC boards to PTS. My question is should I send the SD/SU boards in as well. As I described when I used the shop jimmy kit on the SC board I got a perfect picture back for about 10 minutes which from what I read wouldn't have happened if the SD/SU boards got damaged. After I pulled SC board decided to pull SD/SU and check for shorts on those. All ribbon cable pins looked good. Just looking for advice to see if I should send them in as well just to be sure, thanks.

[ljintexas]

Re: Help Panny tc 55gt31 blinking led

If you do SC, I would do SU/SD too!

[Stal8080]

Re: Help Panny tc 55gt31 blinking led

OK I sent all the boards in for repair and it turns out only the Sc board was bad they are repairing that and sending the SU and SD boards back to me tomorrow. Honestly I'm terrified to plug them all in and turn them on to see what happens. If for some reason something is wrong with the SS board could that damage the SC board again?

[tw2005]

Re: Help Panny tc 55gt31 blinking led

OK I sent all the boards in for repair and it turns out only the Sc board was bad they are repairing that and sending the SU and SD boards back to me tomorrow. Honestly I'm terrified to plug them all in and turn them on to see what happens. If for some reason something is wrong with the SS board could that damage the SC board again?

No, won't happen. they've tested the buffers, they'll run the Sc board up as well.

assuming they're all good it will work, if not I'd expect a different blink code and the SS is not going to damage the SC in this model.

[tw2005]

Re: Help Panny tc 55gt31 blinking led

just take your time, check and double check.Things to keep in mind.

Install all grounding screws and be firm with the SC bolts if they're the old type with no washers.

Make sure the SD/SU buffer board VFG bolts are in

Don't forget the small ribbon between the Sd/Su

The panel ribbons are tricky, keeping it perfectly parallel is the key and insert all the way. Then compare the markers on the ribbons or even to each other and you can usually detect the crooked ones.

Crooked equalls horizontal black lines, badly crooked can end up as shorted and bang.
Don't attempt any ribbon adjustments with the TV running = bang