Panasonic Plasma TH-P50GT30A - 7 blinks

[tw2005]

hallelujah, Back in the land of the cities where I can get some Pannys to fix.

TH-P50GT30A - 7 blinks. Been advertised for a while, price was a bit high, anyway got it down a bit.

person had it from new, already had 1 SC replaced 7 blinks, failed again, same blinks.

Even had the original failed board(bonus)

Original SC was TNPA5335BG (TXNSC11GGKBTH), these were superceeded with TNPA5335(TXNSC11GGKB50). Of course different regions can have different part numbers but the board number and two suffix work out.

Having looked at both the difference with the revised board was that they removed the soldered lands topside and had bare copper for the bolts to mate with. But the same screws were used.

taking it apart , 3 were not tight and the usual marks underneath.

It's looking like 3 x RJP30H2 and 3 x 30F131 shorted on the second board.

on the origninal, I had a quick poke around and looked like just 1 30F131 and the Q661 RJP63G4 gone. Found nothing else obvious .

So as luck would have it, the Q661 on the other was good and I had 1 30F131 still ok on that board.

Swap over, power up 8 blinks nothing popped.

Hello, I've been here before ( https://www.badcaps.net/forum/showth...ht=th-p50st30a) , failed Q102 on SS , RCJ330N25

Replaced that and up and running.

16500hrs, no wonder it's done 2 boards

I'll add photos when it's available.

Nice picture with the filter on the glass for glare.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

Just pooped itself again, somehing popped. 7 blink will get to it and report.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

finally, chinese parts arrived from UTsource.

Board #1: I did a very quick and dirty replacing just Q621 30F131 and Q661 RJP63G4, lasted not long and popped after 2 runs as reported in post #2..

So this time I've replaced the whole bank Q621,622,623 and Q661. It's running again and I'll keep this board in it for testing.

Board #2, which is the revised replacement board. had the common 3 x 30F131 Q401,402,403 + 3 x RJP30H2 Q421,422,423.

Fired up ok, but will retest this after Board#1 has had a good run.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

Just pooped itself again, somehing popped. 7 blink will get to it and report.

my GT has died again, 6 blink. was fine running for a few hours, was turned off and I just went to fire it up again, no pop but a funny low buzz like a shorted panel, bad buffer maybe?

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

same parts failed Q621,622,623 and Q661. Obviously I've missed something, time to put the other board in while I try and nut this out.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

Just pooped itself again, somehing popped. 7 blink will get to it and report.

my GT has died again, 6 blink. was fine running for a few hours, was turned off and I just went to fire it up again, no pop but a funny low buzz like a shorted panel, bad buffer maybe?

This is how it went last time, worked fine for the night, turned off, next day went pop at startup.

[michael dranfield]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

I find that things that go pop when cold and work when they are hot is usually down to a dried out electrolytic capacitor , you want to see the difference it makes to the ESR when you cool a worn out cap with a tin of freezer.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

I find that things that go pop when cold and work when they are hot is usually down to a dried out electrolytic capacitor , you want to see the difference it makes to the ESR when you cool a worn out cap with a tin of freezer.

Not sure, it could be blowing at shutdown

[tom66]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

I doubt this is caused by an electrolytic going bad. More likely if it's giving 6 blinks it's an ER circuit problem, so check the gate driver for the ER circuit. If that's bad that could cause this failure.

[ReeceyBurger123]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

What about a bad Y cap ? I had an Lg42Pg6000 blowing the fets which were 30F131 and it was due to a failed Y cap that I think was in parallel with fets and GND. It was odd as it worked for a while then boom ! The Y cap had leakage across it so and I guess was causing a short between the fets and GND causing them to pop ? Just a suggestion to check them if there are any on this board.

[flocko]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

TW this is not like you? you fail to say but are you are changing IC 501/502 Q 501/531 change them whenever you rebuild these board also check all gate resistors and the little CO8N25 unable to give board number as mind has gone blank. Also make sure the tabs are soldered on correctly. if the tabs are not on right the other IGBTs take to much load and blow, just like our trade unions one out all out Good Luck Flocko

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

TW this is not like you? you fail to say but are you are changing IC 501/502 Q 501/531 change them whenever you rebuild these board also check all gate resistors and the little CO8N25 unable to give board number as mind has gone blank. Also make sure the tabs are soldered on correctly. if the tabs are not on right the other IGBTs take to much load and blow, just like our trade unions one out all out Good Luck Flocko

I'm having trouble tying in what is blowing , and what the kits have and what Tom is suggesting and your suggestions.

Q661 and Q621,622,623 are going out to lunch together. Q401,402,403,421,422,423 are ok,

IC502 drives Q531,Q441,442

IC501 drives Q501,401,402,403

all resistors checkout

with the C08N25 (Q600) is there any sign it's bad or what? Not shorted, maybe I should pull it out I do have 2 new ones just in case.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

schematics etc

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

It's now in SC heaven, Q661 & co fail again. Suspect maybe BD8655FV Ic921 , driver for q661. Other board in and running.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

It's now in SC heaven, Q661 & co fail again. Suspect maybe BD8655FV Ic921 , driver for q661. Other board in and running.

Back to this damn board. reached a dead end and the only clues are Q661, Q621-623 failing. Pretty much checked everything, including PC685.

Anyway, all I could come up with guessing were Q818,819,820, IC921 BD8655 IGBT driver or something missed around Q621-623.

Found nothing spectacular about those tiny FETs, IC921 I have not found any kits or anyone replacing that yet. Was considering borrowing one off another working board.

Anyway < I went back to the opto and probed it in diode and got a reading of 1.6 in both directions, thought that was sus, grab a few other boards and got different results say 1.6 and 0.7.

Pulled it off and no reading either direction, another I had had no reading and 1.4. I'm probing the diode side.

So I reached the conclusion the opto was dead, pilfered off a dead board, now getting 1.4 & 1.6, replaced the usual suspects rjp63G4 & 30F131 that kept blowing and it's back online.

too soon to say it's fixed but maybe the opto was flaky and finally quit. i hope so because I really want this board fixed as a spare.

I guess if I get more than a day out of this things will be looking good as both attempts that failed, worked ok and then failed at startup after a good run. 6 blinks.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

it's still working

[vinceroger69]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

it's still working

Lol thats like me when i test something waiting for the next pop of parts but fingers crossed you have fixed it a long soak test with a few power on/off cycles should prove its ok.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

Lol thats like me when i test something waiting for the next pop of parts but fingers crossed you have fixed it a long soak test with a few power on/off cycles should prove its ok.

Shhhh, it'll hear us.

[tw2005]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

looking good, still has a pulse. I think we got ourselves a live one.

[gdawg]

Re: Panasonic Plasma TH-P50GT30A - 7 blinks

WOW, persistence does pay off. I would have trashed it but now I know better. Thanks for the info.