Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

[ljintexas]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Replace SU and SD

[blowed up viera]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

So I replaced the 6 shorted IGBTs, Q401,2, & 3, and Q421, 2, & 3 on the SC board.
I put the board back in and tested per t-shooting procedure and it looked like SU and SD were good. I powered up the TV and it worked like a champ. Then a day and a half later, it blew up again - all 6 IGBTs shorted again.

Does anyone know why this might be happening? Which component(s) could be causing my IGBTs to be blowing?

[ljintexas]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

SU and SD

[cprem]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Update:
I finally got the RJP63G4 IGBT's and replaced, fired up the SC board with SC50 jumpered and once again fired up for a seconds and died with 7 blinks. This time I found the replaced Q661 RJP64G4 shorted and also found Q600 C08N25 shorted (between D and S). I have ordered C08N25 MOS FET and once I get it will test it and hoping it will work.

I Checked all gate resistors and all of them check out fine.
I checked measured all other IGBT's and no shorts.

Replaced Q661 and Q600 and fired up SC with SC50 shorted hear a short buzz with green LED coming ON and then OFF and both Q661 and Q600 shorted.
Any Idea as to what other component may be at fault? I've all other IGBT's and diodes and they are all fine no shorts. I am suspecting a bad IC921 (IGBT Controler) Pin 23 and 24 control the gate of Q661. Any help would be great!

[tw2005]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Replaced Q661 and Q600 and fired up SC with SC50 shorted hear a short buzz with green LED coming ON and then OFF and both Q661 and Q600 shorted.
Any Idea as to what other component may be at fault? I've all other IGBT's and diodes and they are all fine no shorts. I am suspecting a bad IC921 (IGBT Controler) Pin 23 and 24 control the gate of Q661. Any help would be great!

I think replacing the driver Ic could be a place to start, what board number is this?

[tom66]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Replaced Q661 and Q600 and fired up SC with SC50 shorted hear a short buzz with green LED coming ON and then OFF and both Q661 and Q600 shorted.
Any Idea as to what other component may be at fault? I've all other IGBT's and diodes and they are all fine no shorts. I am suspecting a bad IC921 (IGBT Controler) Pin 23 and 24 control the gate of Q661. Any help would be great!

Have you tried using a bulb current limiter?
https://www.youtube.com/watch?v=ROYHWY79784

[tw2005]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

have a look at this kit. usually this guy has the most complete kits and has done a lot of work with panny boards



You can see a driver ic and also the associated driver transistor Q531 IC502

D401 D421 Q401 Q402 Q403 Q421 Q422 Q423

I don't know if it's just these that you need or try working your way back in cct from q601 etc to that other driver and parts there after.

there's probably a few different types of failure, very hard to find a kit that covers all

[cprem]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

I think replacing the driver Ic could be a place to start, what board number is this?

The board # is 5335BK TNPA5335 MOD# TC-P55GT30

[blowed up viera]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

An overdue follow-up to my 10/26 post:
I took off the IGBTs that I had soldered on in my original repair as all 6 were blown again. I also took off their accompanying diodes even though they tested OK with a meter, I figured they're low hanging fruit so why not change them out.

So, when my second repair kit from shop jimmy arrived, I replaced the 6 IGBTs and 2 diodes. I didn't bother with the 6 R15 resistors as the originals tested fine and were likely beyond my soldering expertise and the two other smaller components (IC + transistor) were definitely beyond my comfort level. I installed my twice repaired SC board back to the TV and it worked. After a couple hours, I noticed an audible oscillating/buzzing sound and isolated it to emanating from the SC board. It sounded like it was coming from one of the diodes in the middle of the board that I had just soldered on. After further online research, this audible anomaly can be fixed by improving the grounds on the boards.

Even though the repair kits come with better screws, I originally chose not to use them as I thought the original screws were superior. When I took the original screws out and installed the replacement screws, the noise went away and my TV has been running fine since. It gets a lot of usage as it's the only TV in a 5 person household.

I hope others can learn from my mistake: use the replacement screws! The replacement screws have lock washers that bite into the metal for a superior ground.

[tw2005]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

An overdue follow-up to my 10/26 post:
I took off the IGBTs that I had soldered on in my original repair as all 6 were blown again. I also took off their accompanying diodes even though they tested OK with a meter, I figured they're low hanging fruit so why not change them out.

So, when my second repair kit from shop jimmy arrived, I replaced the 6 IGBTs and 2 diodes. I didn't bother with the 6 R15 resistors as the originals tested fine and were likely beyond my soldering expertise and the two other smaller components (IC + transistor) were definitely beyond my comfort level. I installed my twice repaired SC board back to the TV and it worked. After a couple hours, I noticed an audible oscillating/buzzing sound and isolated it to emanating from the SC board. It sounded like it was coming from one of the diodes in the middle of the board that I had just soldered on. After further online research, this audible anomaly can be fixed by improving the grounds on the boards.

Even though the repair kits come with better screws, I originally chose not to use them as I thought the original screws were superior. When I took the original screws out and installed the replacement screws, the noise went away and my TV has been running fine since. It gets a lot of usage as it's the only TV in a 5 person household.

I hope others can learn from my mistake: use the replacement screws! The replacement screws have lock washers that bite into the metal for a superior ground.

"low hanging fruit" I'll have to remember that one.

So that's good news but certainly ignoring the new screws is asking for a repeat. Somewhat confused how you thought they were superior and countless mentions of replacing them.

So in summary it was the kit plus additional parts not included , driver IC and another transistor that fixed it?

[blowed up viera]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Yes, I guess I willfully ignored the mentions of others replacing the screws. The original ones looked bigger like they would make better contact. I hadn't considered the added advantage of a lock washer that the new screws offered.

So, it was replacing the IGBTs (and maybe the diodes) plus improving the grounds that ultimately fixed my issue. The other parts that came with the kit (tiny IC, small transistor, and 6 tiny 15 ohm resistors) didn't come into play for my repair. No parts that weren't included in the kit were needed.

[TommyV]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Hi, new to the forum. Sunday, my TC-P50GT30 popped after being on for about 30 secs. Now I have the 7 blinks error code.

I spent a lot of time Sunday and Monday reading anything I could find about this error code. I found this thread and also a Panasonic service manual during the process. So here's what I did:

Removed the back of the set. Identified the SC board and isolated the SU and SD boards by removing the 4 ground screws and disconnected the SD42 and SD46 as well as SU41 from the SC board. I jumped the pins at SC50 and powered up the set. Still got the 7 blinks.

I tested for continuity to ground at the 3 locations on the SD board posted by tw2005 in post #84 of this thread. I set my multi meter at the highest setting and none of these were shorted, but I had trouble getting consistent readings.

Next I went to slide 54 of the service manual and tested continuity to ground at
1. Junction of R696~R699 (TPSC1/VSCN-1)
2. Pin 3 of IC724 (VF-%V)

No short at either of these locations. The decision tree on the next slide says replace the SC board.

I didn't check for short or low resistance of the Vsus, Vda or P15V mentioned in slide 50 of the service manual as it talked about removing the residual charge from the Vsus and Vda lines by momentarily grounding them through a 500 ohm resister (at least 5 watts) and I didn't have anything like that laying around and was worried about doing the wrong thing and regretting it later.

I don't have confidence in my soldering abilities, so I sent the board to PTS Electronics in Bloomington, IN for refurbishment. We'll see if that was the problem in a few days.

[tw2005]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Hi, new to the forum. Sunday, my TC-P50GT30 popped after being on for about 30 secs. Now I have the 7 blinks error code.

I spent a lot of time Sunday and Monday reading anything I could find about this error code. I found this thread and also a Panasonic service manual during the process. So here's what I did:

Removed the back of the set. Identified the SC board and isolated the SU and SD boards by removing the 4 ground screws and disconnected the SD42 and SD46 as well as SU41 from the SC board. I jumped the pins at SC50 and powered up the set. Still got the 7 blinks.

I tested for continuity to ground at the 3 locations on the SD board posted by tw2005 in post #84 of this thread. I set my multi meter at the highest setting and none of these were shorted, but I had trouble getting consistent readings.

Next I went to slide 54 of the service manual and tested continuity to ground at
1. Junction of R696~R699 (TPSC1/VSCN-1)
2. Pin 3 of IC724 (VF-%V)

No short at either of these locations. The decision tree on the next slide says replace the SC board.

I didn't check for short or low resistance of the Vsus, Vda or P15V mentioned in slide 50 of the service manual as it talked about removing the residual charge from the Vsus and Vda lines by momentarily grounding them through a 500 ohm resister (at least 5 watts) and I didn't have anything like that laying around and was worried about doing the wrong thing and regretting it later.

I don't have confidence in my soldering abilities, so I sent the board to PTS Electronics in Bloomington, IN for refurbishment. We'll see if that was the problem in a few days.

I think you're ontrack and should be happy after the board goes back in. Pay attention to making sure all the gnd points are clean for that board and also see if you can get the preferred bolts with washer and spring washer.

you may have noticed the SC bolts may have been loose and burn marks under the heads.

Failing that , I'd use the old ones with a dab on non permanent loctite and do them up snug.

Bad earths are part of the problem with this generation of pannys.

[TommyV]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

I think you're ontrack and should be happy after the board goes back in. Pay attention to making sure all the gnd points are clean for that board and also see if you can get the preferred bolts with washer and spring washer.

you may have noticed the SC bolts may have been loose and burn marks under the heads.

Failing that , I'd use the old ones with a dab on non permanent loctite and do them up snug.

Bad earths are part of the problem with this generation of pannys.

There were maybe two screws that 'might' have been a little loose, but no scorch marks anywhere. The screws had flat and lock washers.

One weird thing is that the fan above the SC board has three mounting points. Only 2 of them had screws, the third was missing the rubber buffer washer and the screw.

Thanks for all your contributions to this thread!

[Test Ickles]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Sorry to dig up an old thread, but my Panasonic TC-P50GT30 just went into the 7 blinking lights mode. This forum has been very helpful in diagnosing the problem. I have one question regarding troubleshooting the SC board: aside from ordering the Panasonic jumper jig and further delaying my fix, what is everyone using as a jumper for the SC50?

I apologize if this is a stupid question. I'm not very tech savvy. Thanks folks, I'm glad I found this forum where so many people are willing to help each other out.

I have the same question. If I do not have any jumpers what can I use to short the SC50?

[Moreno83]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

You can use a screw. Just place the screw between those pins so it gets stuck. Turn on the tv without the buffers , still 7 blinks then SC board is bad.

[jason123]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Rookie mistake - I know.. I'm hoping one of you Gurus can help me out.. I was working on the SC board (TNPA5335 SC) of a Panasonic TC-P50GT30, and the soldering iron slipped and I accidentally knocked 2 small resistors off the board.. I found one, but I can't find the other one. I would be grateful if some one can tell me the value of Resistors R588??? or just read off the numbers?

[tw2005]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Rookie mistake - I know.. I'm hoping one of you Gurus can help me out.. I was working on the SC board (TNPA5335 SC) of a Panasonic TC-P50GT30, and the soldering iron slipped and I accidentally knocked 2 small resistors off the board.. I found one, but I can't find the other one. I would be grateful if some one can tell me the value of Resistors R588??? or just read off the numbers?

Glad I only had to respond to two posts.

https://www.badcaps.net/forum/showthread.php?t=57665

22K ohms

Of course if you simply went to the service manual and located it in the spare parts list that too would tell you.

R16588 D0GB223JA065 M 22KOHM,J,1/10W

[Behemot]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

All these sets damage is usually caused by arcing at the screws that ground the circuitry some of the better rebuild kits give replacement screws and it is recommended that some solder should be carefully added to the ground pads at the screw holes!

Just got P50VT30E for repair and noticed one loose screw on the SC board. So that may be what killed the transistors? Do not see any arcing clues, it is on the very opposite side of the board from the bad transistors. Been thinking about using igher-rated transistors if these go bad so often, but from what I've read so far, it seems the problem usually lies elsewhere and they go bad only as a result of it?

I am just about to order some stuff from DK, should I take the FETs from there, or some complete kits from fleebay? Or possibly does anybody know which of the drivers and SMD resistors are in these kits so I can get them separately from DK?

[Behemot]

Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

Removed the board, it was arcing almost under each single screw to the point the solder oxidised and turned black. All three of the power FETs are shorted, so which kit or components should I grab to ensure everything else whch may also be bad is OK now?