Panasonic Plasma TC-P50GT30 7 blinks SC board shorted

[Chaks]

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

I was watching live show on panasonic TH-P42XT50D when my 4 year old kid threw a golf ball and the screen developed a 2inch 'x shape' crack on the bottom left of the plasma panel. The tv shut off immediately. when I tried to switch on the tv I am greeted with 7 red Blinks. The panel lit up all white for a second or two and shuts off. The power led continue to blink 7 times with pause in between.
I opened the back cover and noticed that there are
1. power board with sustain drive in single pcb.
2. Sc board with buffers in a single pcb.
3. C1 and c2 boards connected by ribbon cable.
4. 'A' main board
A four wire Power cable from power board goes to sn1 connector on the sc board.
Ribbon cable from 'A' board goes to sc20 on sc board.
I can solder and usually fix most of the issues in audio amplifiers myself. But I need help here as how to diagnose the problem and repair it. Though there is a visible crack on the plasma screen the tv lits up all white for a second or a two makes me feel a bit better that the panel is alive.
Please help me to diagnose the problem.

[blowed up viera]

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

Yes, I put a meter on the buffers and tested per a related post. My meter isn't the best but I didn't see any low values that would indicate a failure.

When I'm ready, I'll put the repaired SC board back in while still isolating the buffers and go through the diagnostics to make sure the buffers are good.

[tw2005]

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

I have the same issue with 6 blown IGBTs on my TC-P50GT30 SC board. I'm not sure if any ICs are also fried. The SD and SU boards seem OK. I'm not the most experienced solderer but I've done some over the years. Is there solder that I need to melt underneath the IGBTs, or just the pins? If I have to melt underneath, is there a special iron I need?
Thanks.

-It failed with a very loud bang and flash.

yes , thos metal abs run the back of the transistor body and it can take a bit of heat to get it flowing because the board acts as a heatsink. maybe check out moduslinkpts and see what they're charging.

hope you checked the buffers with a meter and not just a visual

[blowed up viera]

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

I have the same issue with 6 blown IGBTs on my TC-P50GT30 SC board. I'm not sure if any ICs are also fried. The SD and SU boards seem OK. I'm not the most experienced solderer but I've done some over the years. Is there solder that I need to melt underneath the IGBTs, or just the pins? If I have to melt underneath, is there a special iron I need?
Thanks.

-It failed with a very loud bang and flash.

[electronicsurplus]

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

'tw2005' IF you look at the center of the screen, you will barely make out the image which is supposed to say "No Signal" in a square (Supposed to be Blue Box)

Thank you very much for your response

Hopefully, this info will help someone in need out there

I can tell you now. It was a very Arduous task learning these Panasonic's Problems and, took a bunch of time and tinkering to finally get it. It was very frustrating task.

Now, I would like to pass on our success.

Thanks again
Aimee

[electronicsurplus]

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

Also, IF you find that the 30F131s are shorted on the output side (closest to the buffers (SU/SD Boards) then I recommend testing the buffers for shorts. There is a discussion here how to test buffers using a Multi Meter (I like using the Diode test mode using the +Positive lead on one of the Pads and run the - Negative lead, in a slow zipper like fashion on each of the output pins (Connecting to the Ribbon Cable) to make sure none of the pins show low resistance. You need to do this test slowly because, I have found one or two of the pins with very low or no resistance and, shorted the SC Board right out rapidly.

If the opposite 30F131's are shorted, this is most likely due to overheating, Power Surge or, other problem. Either way please do test the buffers to save yourself a bunch of time and expense

Good Luck and Happy Repairing
Let's all work together to keep these working and save our $$ for something else besides constantly sending to China ; )

[electronicsurplus]

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

It turned out that some of these models do need the Exact Suffix or, at least need to be from the same size TV. I was using a SC Board from a 55" and, the picture it produced was similar to a Bad SS or X/Y Board, weird picture with only static and red dots

I also want to add that we have rebuilt many (over 50 of these SC Boards so far) and, have gotten away with using ONLY the 30F131 IGBTs. In fact, the kit that ShopJimmy sells provided these in place of the RJP30H2s. We have never bothered using any of the other components (as long as the resistors are tested not to be open) and, they have successfully worked on both the TC-P50XXX AND THE TC-P55XXX SC Boards Since, we order the 30F131s by the roll of 100pcs, which ends up costing about $4.00 or so per TV

We also use Heatsink Strips on ALL repairs in order to keep the IGBTs cooler Which I highly recommend either using a small fan or heatsinks with Silicone adhesive because these IGBTs do run quite hot and, this has extended the longevity (Have not had one returned yet.(Knock on wood) : )

Good luck

Hopefully this may help somebody to keep these lemons from the Landfills

[tw2005]

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

I have replaced all of the 30F131 and RJP30H2A in the SC Boards. There are no longer any shorts yet, I still have a Static screen with brightness but, NO video. The same thing happened on all 3 SC Boards I have tried.

Buffers test perfect, SS No Shorts.

The same exact thing is happening with 2 different Exact same models

Is there something I am missing?

See the attached pics

double check the Sc transistors, i'm seeing kits with RJP63G4 and C08N25 transistors i n them plus 7.5 ohm resistors for the 30f131 and RJp30H2

I can't make out brightness or static in the photo. is that a couple of weird bright streaks in the bottom left corner?

[electronicsurplus]

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

I have replaced all of the 30F131 and RJP30H2A in the SC Boards. There are no longer any shorts yet, I still have a Static screen with brightness but, NO video. The same thing happened on all 3 SC Boards I have tried.

Buffers test perfect, SS No Shorts.

The same exact thing is happening with 2 different Exact same models

Is there something I am missing?

See the attached pics

[tw2005]

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

Hello,

What is the exact difference between RJP30H2A and 30F131. I thought I read somewhere that someone was using one in place of the other but, I cannot find the post anymore

Any help would be great

Aimee

hard to find exact specs but looks like both are 360V but the RJP has higher current capacity 35A ( 30A) 250A pulsed (200A pulsed) so you may get away with the RJP for the Toshiba IGBT but going the reverse would be below original spec.

[electronicsurplus]

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

Hello,

What is the exact difference between RJP30H2A and 30F131. I thought I read somewhere that someone was using one in place of the other but, I cannot find the post anymore

Any help would be great

Aimee

[COLLETTA]

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.

Hello slyck68,
I'm not an expert, I can give you a little help, however, Sevenqi, to post "6" used an IDE hard drive jumper! See if you can recover it too.

I after much difficulty in tradurvi are managed through your help to figure out where the problem lies. I have a Panasonic TX-P50GT30E, after the fall of lightning went with 7 flashing lights.
SC card looks good, while the card is ON shorted, I ordered a new one, will arrive tomorrow, hope everything goes ok!
Many thanks for the help, aggiorerò as soon as possible.

[slyck68]

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

So long as there are no shorts on the input side and no shorts between the output pins and Vfg it won't. You can always leave the SD/SU off and jumper SC50 on the Sc and fire it up for testing. If it starts with no error blinks then the Sc is good. If the worst happened after hooking up the buffer at least you knew the Sc was good.

If you still have a defect on the lower buffer then you may have to look into it then.

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.

[CoinCoin88]

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

I think you may mean SC2, but no short is no guarantee but certainly a step in the right direction.

indeed, SC2. I did not have the ref in my mind and had to guess
Obviously no short is not a guarantee that everything is fixed, but it's a good start

[tw2005]

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

Question: In step #2 I am assuming the only plugs connected to the SC board are the input SC20 and the flat ribbon cable from A board, correct?

SC20 is the ribbon from the A board. SC2 is power. Both need to be connected to test the SC board

[dsi]

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

Update:
Received the parts today, replaced the 6 transistors (3 RJP30H2A, 3 30F131), TV works great now.

Steps:
1. Replaced the bad 6 transistors with the new one.
2. Install the board back to TV, but NOT connect to the buffer boards (SD/SU) (I even disconnected the grounds, no physically touch between the SC and the two buffer boards).
3. Shorted the SC50 (I used an old IDE hard drive jumper)
4. Plug and Turned on the TV, it powered up constantly, no blinks any more, TV response to the remote control.
5. Unplug the power cord from the wall, wait for 5 minutes.
6. Connected the SC board with the SU/SD board firmly (connectors and grounds).
7. Plug and turned on the power supply, TV lite up ! Everything works !

Question: In step #2 I am assuming the only plugs connected to the SC board are the input SC20 and the flat ribbon cable from A board, correct?

[dsi]

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

Thanks for the feed back guys. When I test Q531 the way that tw2005 was recommending it looks like a two diodes running in opposite directions. The short I have between the two outside legs could be coming from some of the shorted parts. They are still on the board. New one should be coming on Monday and I will compare and report back.

[tw2005]

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

Hi,
I did not test Q531 the way you described (I just did mine as tw2005 suggested). You can always check on the one you'll get with th repair kit if it reads shorted between the legs you describe. If it doesn't, assume the one on your board is fried. If it does, well, it's just like yours on the board, so it's probably normal.

A good indicator of correct repair is that there is no short anymore between both input pins (SC20)

I think you may mean SC2, but no short is no guarantee but certainly a step in the right direction.

[tw2005]

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

Hello,

New member here with 2011 TC-P50GT30 and 7 blinks.
Thanks to all the info here I have confirmed that the SC board is bad with all the 6 transistors shorted out. Q531 read open between the legs as listed by tw2005 with my meter on 20M range, but I have short on the two outside ones (the side with 3 legs). I am assuming it is bad??? IC724 looks good. Since I need to fix my TV quick I have ordered new board, but still may try to fix my original one, possibly for future use since the kits are still available.
Please let me know if I am missing anything else to check.

Thanks

If we're talking those 5 pin npn/pnp 3Y transistors, end to end on the 3 pin side will show short.

In cct opposing pins on either end should be in megohms ( about 3meg in cct ) that's where i check.

[CoinCoin88]

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

Hi,
I did not test Q531 the way you described (I just did mine as tw2005 suggested). You can always check on the one you'll get with th repair kit if it reads shorted between the legs you describe. If it doesn't, assume the one on your board is fried. If it does, well, it's just like yours on the board, so it's probably normal.

A good indicator of correct repair is that there is no short anymore between both input pins (SC20)