Panasonic TX-P42S21BA - 7 red flashes

[Nurbit]

Hi guys
I've recently acquired the TV mentioned in the title.
When turned on, it flashes the green light quickly and then flashes the red light 7 times.
I've looked at several other threads about Panasonic TVs and was going to try one of Tom66's solutions but because the boards have different SD,SU,SS names, I thought I'd post on here first to see if anyone can help.

From what I can gather, the 2 boards on the left (sometimes call SU and SD on certain models) are called SM and SC on this TV.

I'm happy to isolate the boards but could do with knowing where the jumper wire needs to go to and from on this particular model.

I can add photos of the TV's guts if needed.

Any help would be greatly appreciated.

Thanks

[tucocaps]

Re: Panasonic TX-P42S21BA - 7 red flashes

I think 7 blinks almost always requires a panel replace and/or indicates a repair that requires panel replacement. I have a similar post above yours We'll see what the other say. Good luck.

[Nurbit]

Re: Panasonic TX-P42S21BA - 7 red flashes

Hi Tucocaps

I'm still playing with the TV and have found that sometimes, it does display a distorted image which quickly fades before the red flashing starts.
I'm starting to suspect that it's a fault with one of the MOSFETS on the SC board...... but I could and probably will be wrong :/

[Shinju]

Re: Panasonic TX-P42S21BA - 7 red flashes

7 blinks is SOS for SC board, I have a Panny here with no damage to the screen at all and I get a 3 blink when everything is connected and a 7 when the SC board is the only thing connected.

SC boards for these are NOT CHEAP, so test everything before sticking a new board in so that you dont blow that one up too

Tom66 or TW2005 will probably chime in, they know a ton about plasma panels, TW2005 seems to be the Panny expert

[Nurbit]

Re: Panasonic TX-P42S21BA - 7 red flashes

Quick update -
After power cycling the TV a few times, it's now working perfectly....

I've tried leaving it a while and then turning it back on thinking that the fault would re-appear and it hasn't yet.

I'm going to leave it alone over night and try it again in the morning. I suspect it will fail again.

Usually, I'd suspect a bad capacitor or two to cause this kind of fault but I read Tom66's statement in another thread about Panasonics not having cap problems.

I'll see what happens in the morning, if it's dead again, I may start pulling caps and testing them with my ESR meter.
Until then, if anyone has any other ideas I'd love to hear them.

[Nurbit]

Re: Panasonic TX-P42S21BA - 7 red flashes

7 blinks is SOS for SC board, I have a Panny here with no damage to the screen at all and I get a 3 blink when everything is connected and a 7 when the SC board is the only thing connected.

SC boards for these are NOT CHEAP, so test everything before sticking a new board in so that you dont blow that one up too

Tom66 or TW2005 will probably chime in, they know a ton about plasma panels, TW2005 seems to be the Panny expert

Replacing the board?? That's cheating
I'll be attempting a repair on mine instead

[Shinju]

Re: Panasonic TX-P42S21BA - 7 red flashes

Replacing the board?? That's cheating
I'll be attempting a repair on mine instead

replace/repair either or. the kits for some of these SC boards are hard to get too. the one for mine has been unavailable for months.

So it sits

[Shinju]

Re: Panasonic TX-P42S21BA - 7 red flashes

Oh and snap photos of everything and post em, it will help diagnose stuff better if they can see it.

[Nurbit]

Re: Panasonic TX-P42S21BA - 7 red flashes

replace/repair either or. the kits for some of these SC boards are hard to get too. the one for mine has been unavailable for months.

So it sits

Have you tried looking for the components individually?
You might be better off making your own "kit" up. It might cost you slightly more if you have to buy a 10 pack of some parts but at least you'll have them on stock :-)

[vinceroger69]

Re: Panasonic TX-P42S21BA - 7 red flashes

Quick update -
After power cycling the TV a few times, it's now working perfectly....

I've tried leaving it a while and then turning it back on thinking that the fault would re-appear and it hasn't yet.

I'm going to leave it alone over night and try it again in the morning. I suspect it will fail again.

Usually, I'd suspect a bad capacitor or two to cause this kind of fault but I read Tom66's statement in another thread about Panasonics not having cap problems.

I'll see what happens in the morning, if it's dead again, I may start pulling caps and testing them with my ESR meter.
Until then, if anyone has any other ideas I'd love to hear them.

from what ive read most sc boards fail with shorted/blown parts as your set works intermitantly it maybe ok lets see what toms and tw2005 thaughts/advice is.

[tw2005]

Re: Panasonic TX-P42S21BA - 7 red flashes

So the board is a TXNSC11DEK, tnpa5105ad. I'd measure all the voltages if it's running on the SC board.

One may be close to the threshold of shutdown.

TPVSUS,TPVAD,TPVSCN,TPVe

If it becomes more consistant faulting, then next step would be to isolate the buffer board and jumper SC50 and see if it fixes it straight away or still there indicating SC.

I have had a 2009 HD which had 7 blinks and could get it to fire intermittently. I think VAD was low and on that SC it had an adjustment pot which made no difference.

Never went any further with it, board swap, that waws before I got interested in saving these boards.

Not sure where you'd start for SC that has not blown the transistors, but getting some reading may help give a clue.

I've also had a bad octal buffer IC at SC20 cause 7 blink.

So when running the picture is good?

[Nurbit]

Re: Panasonic TX-P42S21BA - 7 red flashes

Thanks for the reply.

Came to the TV tonight and it worked on the second power cycle.... now is still working.

The picture is absolutely perfect so far although I've only tested it with a raspberry pi as that's all I had near me.

[Nurbit]

Re: Panasonic TX-P42S21BA - 7 red flashes

Quick update on this TV.

After a couple of weeks of having to power cycle the TV a few times, the problem went away.
I've been using daily ever since and the problem hasn't returned... yet

[tw2005]

Re: Panasonic TX-P42S21BA - 7 red flashes

Quick update on this TV.

After a couple of weeks of having to power cycle the TV a few times, the problem went away.
I've been using daily ever since and the problem hasn't returned... yet

Amazing, may it live on

Funny thing is the moment you make a statement like this it'll go caput.

Like last week I was having a cold one with a mate I revived a panasoic 2006 from the dump for $20. we were just amazed how good and bright that SD picture was. He's had it for months

Next day , he said bugger, we jinxed it. Died today just shutdown.

Sounded terminal like the main board, so he invested in a 4yr LG, his choice.

Not much to pick from where we are.