Panasonic LSEP1287 4 blinks

[Russ300]

Hi guys, So im trying to fault find a Panasonic 42" plasma - P42x20b, the 4 blinks tells me its a power board SOS problem, caps look OK, FET's seem to test ok, I have standby voltage, I think i have 15Vdc, Then it shuts down faster than i can measure anything else, i dont really want to pay 350 for a second hand boeard, thanks in advance.

[tw2005]

Re: Panasonic LSEP1287 4 blinks

Check the SS board Vsus rail, shorted RJP30E4 x 4

[tw2005]

Re: Panasonic LSEP1287 4 blinks

https://www.badcaps.net/forum/showth...hlight=rjp30e4

[Russ300]

Re: Panasonic LSEP1287 4 blinks

OK so i figured the SOS signal is coming from this chip (pin 17 /SOS4_H) ?

So what signals would generate this alarm if missing ?

[tw2005]

Re: Panasonic LSEP1287 4 blinks

OK so i figured the SOS signal is coming from this chip (pin 17 /SOS4_H) ?

So what signals would generate this alarm if missing ?

Ok, I'll make it easier for you. The P board is shorted by the SS board(most likely) on the 200v vsus line and triggering the SOS4.

Disconnect SN2, Sn20, SS11, P35, and the 3 white ribbons at the A board. Turn TV on. Should turn on and stay on and you'll be able to check all voltages if you wish. Don't reconnect any power leads for 5-10 mins, don't run the TV more than 30secs like this.

If it all goes to plan, this proves A and P boards are ok. Then investigate the SS ( SS11 TPVSUS will be shorted)

[Russ300]

Re: Panasonic LSEP1287 4 blinks

Ok, I'll make it easier for you. The P board is shorted by the SS board(most likely) on the 200v vsus line and triggering the SOS4.

Disconnect SN2, Sn20, SS11, P35, and the 3 white ribbons at the A board. Turn TV on. Should turn on and stay on and you'll be able to check all voltages if you wish. Don't reconnect any power leads for 5-10 mins, don't run the TV more than 30secs like this.

If it all goes to plan, this proves A and P boards are ok. Then investigate the SS ( SS3 will be shorted)

Thanks. Sorry, I didnt read the reply before posting again

[tw2005]

Re: Panasonic LSEP1287 4 blinks

Thanks. Sorry, I didnt read the reply before posting again

[tw2005]

Re: Panasonic LSEP1287 4 blinks

If your going to run the TV with just the SS isolated, make sure SS11 and SS3 are disconnected. i have managed to blow up a good SN board powering up forgetting to isolate SS3.

Sometimes both SN and SS blow together due to the SS being connected to the SN

[Russ300]

Re: Panasonic LSEP1287 4 blinks

Check the SS board Vsus rail, shorted RJP30E4 x 4

Yep, all shorted, no further testing. Sourcing equivalents.

[Russ300]

Re: Panasonic LSEP1287 4 blinks

Are these suitable replacements ?

[tw2005]

Re: Panasonic LSEP1287 4 blinks

Are these suitable replacements ?

Nope. Should be able to get the originals or could try IRG7S313UPBF which are only 330V 40A although FGD4536, 360 V PDP Trench IGBT be closer but smaller packaged.

[Russ300]

Re: Panasonic LSEP1287 4 blinks

ok, thanks, I will have to purchase from eBay for conveinence

[Russ300]

Re: Panasonic LSEP1287 4 blinks

Bugger ! Replaced the 4 RJP30E4, powered it up, a large buzzing noise occurred, a flash of smoke from the right hand side of the set as you look at from the front, now im getting 8 red flashes :-(

[tw2005]

Re: Panasonic LSEP1287 4 blinks

Sounds like the SN was bad also. I guess the SS is shorted again too. Did you check out the Sn at all for shorted IGBTs. They're a bugger of a Tv to get right.

[tw2005]

Re: Panasonic LSEP1287 4 blinks

maybe have a read

https://www.badcaps.net/forum/showth...npa5066&page=4

may give some clues what can fail.

[Russ300]

Re: Panasonic LSEP1287 4 blinks

OK so the RJP30E4 's survived, i have thre shorted components on SN

DG501RP
FU20 TM5S
RJP63f3A

UT source have all these in stock but something wrong with their payment page, any other reliable sources you could recomend to supply all these in one easy transaction ?

[tw2005]

Re: Panasonic LSEP1287 4 blinks

OK so the RJP30E4 's survived, i have thre shorted components on SN

DG501RP
FU20 TM5S
RJP63f3A

UT source have all these in stock but something wrong with their payment page, any other reliable sources you could recomend to supply all these in one easy transaction ?

I'm rather skeptical that that is all that is blown if the RJP63F3A is shorted. No I have no other source I've tried, there are some kits, but I have no idea if they are complete enough. Which 501RP and 20TM5S blew?

[Russ300]

Re: Panasonic LSEP1287 4 blinks

Rjp63 - q661
Fu20 - d481
Dg501- q451

This is turning into something financially uneconomical to repair if this doesn't fix it

[tw2005]

Re: Panasonic LSEP1287 4 blinks

Rjp63 - q661
Fu20 - d481
Dg501- q451

This is turning into something financially uneconomical to repair if this doesn't fix it

Unless you get the bits from china, yes as I have a feeling there's a reasonable chance the SN may still be bad with just those replaced.

maybe PM Flocko if he's around? He's done a few of these sets now and had a couple of failed attempts on the Sn as have I but has more experience.

I have a SN laying around to compare readings to and a SS.

[Neelix]

Re: Panasonic LSEP1287 4 blinks

Yeah, with Q661 shorted, you probably have parts faulty in the IC773 circuit as well. You should take tw2005 up on his offer to give you readings from his SN board and compare the readings then to your board. It really helps