Panasonic sc tnpa5081 rebuild

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Ok I'll check out the SS board thanks for the heads up. I have 78L05 SMDs at work come to think of it. Q622 & Q621 seem to be ok, the only lower resistance I see is 47k across emitter to insulated gate, which looks like it should read be with R763 being there.

All my bad IGBT failed shorted, 47k sounds normal like you say, I tested mine in diode mode in and out of cct. There's a method where you have turn the IGBT on first with the volatge out of the probes, google testing IGBT, there's a handy youtube somone did.

I only pulled out the shorted IGBT.

[rmalbers]

Re: Panasonic sc tnpa5081 rebuild

Hey guys, slight thread bump... this is the best source of info for this board that I was able to find. My TC-P54G25 just bit the dust, pretty much 3 years on the nose from when I bought it! Got the 10 blink code, so I disconnected the ribbon & power to the SC board and it went to 6. My first question is, is the damage usually isolated to the SC board or do the SD & SU boards get fried too? Thanks to this thread I was able to find some components that were bad. I'm an amateur when it comes to troubleshooting, I work with electronics as my job but we're far more into the replacement industry if you know what I mean. So far here is my list of dead components (checked when removed from circuit):

D482
Q452
Q401
Q402
Q403
Q421
Q422
Q423
Q660
Q661
R452
R551

Is it assumed the FET drivers always go on these(IC501, IC521)? Also, what's the best way to check those double transistors? (Q551, Q521, Q501, Q531) I don't have the board in front of me right now but no pins were shorted except where the bases connect obviously. One other thing I found was a 13 ohm reading across the 5V reg. from common to output (IC771). I took it out of circuit and the resistance is still there. The reg. itself is showing about 5.6k now if I remember correct.

I think I've got most of the same components bad in my 54G25 (also three years old when it quit this summer), at least in my initial checking. My problem is I'm not sure I can solder/replace these tiny little components, this stuff is crazy small. There is a hole in R551 in mine!

[Stryff]

Re: Panasonic sc tnpa5081 rebuild

I think I've got most of the same components bad in my 54G25 (also three years old when it quit this summer), at least in my initial checking. My problem is I'm not sure I can solder/replace these tiny little components, this stuff is crazy small. There is a hole in R551 in mine!

Ah it can be done, a small conical tip and thin solder go a long way. A day without sugar & caffeine helps too haha.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

I find if you have 2 soldering irons to heat the pins on both sides that helps otherwise you can lift pads. I have head worn magnifier to assist , makes a huge difference.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

That SS from the TC-P60S30 , a little suspicious but that is not shown as the SS board for that model at SJ. 54" was the biggest for that generation to my knowledge. The picture is correct for TNPA5082

58" has TNPA4156, 60S30 is all surface mounted IGBTs.

I would double check with the seller or pick another if you choose to.

[XxWEISERxX]

Re: Panasonic sc tnpa5081 rebuild

Is the repair kit a good buy from the guy in the UK? TV I got is a TC-p50G20 did the trouble shooting thing and it points to the SC board TNPA5081 got the TV for 150 bucks would like to get it to work. Maybe someones got a board to off load and take mine in as a repair or a Kit i can order up in the states?

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

I think it's a bit pricey, if you're going to do that you might as well source them yourself although a couple of parts are tricky to source . Have you repaired boards before?

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

you'll have the check out / test the buffer boards to see if shorted too.

What code did you start with on the TV? SOS4 disconnect SC now SOS6?

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

They popup from time to time, the cheaper ones I saw recently have gone, unlucky there was a complete boardset for yours a week or 2 ago in the US on ebay.

The old supply/demand no bargains at the moment. If yours is not too bad and you have the ability and the buffers are good you may get it done for $50 or less.

Just need patience, skill and some luck.

http://www.ebay.com.au/itm/PANASONIC...item4d13532a27

http://www.ebay.com/itm/PANASONIC-TC...item1c382096b6

[rmalbers]

Re: Panasonic sc tnpa5081 rebuild

Where are you guys getting the schematics for this board? Is it something you can share by any chance? I want to make sure that I find/test every part related to the bad parts I find.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Where are you guys getting the schematics for this board? Is it something you can share by any chance? I want to make sure that I find/test every part related to the bad parts I find.

I'd give you a direct link but it's playing up. http://elektrotanya.com/

[rmalbers]

Re: Panasonic sc tnpa5081 rebuild

Thanks, got it:
I've been on that site before for other stuff but didn't know they had this.

[rmalbers]

Re: Panasonic sc tnpa5081 rebuild

Does anyone have any theories on what causes the SC board to blow components? Would a surge protector help, might it be something coming over the AC power line? What I getting at is there anything I can do to prevent this from happening again.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Nope, I was hoping to come up with one but the failure point vary a little however There are some parts which failed on all 3 boards I did and they were Q661,IC773,Q702.

I know if that inverter cct is not operating Q661 just blows.

[Stryff]

Re: Panasonic sc tnpa5081 rebuild

Does anyone have any theories on what causes the SC board to blow components? Would a surge protector help, might it be something coming over the AC power line? What I getting at is there anything I can do to prevent this from happening again.

I can tell you since day 1 with my set, it had noticeable buzzing from the SC side, especially under high load (white screens). Not sure if that is intended but with my S60 it is near silent.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

I can tell you since day 1 with my set, it had noticeable buzzing from the SC side, especially under high load (white screens). Not sure if that is intended but with my S60 it is near silent.

I find if the mounting screws are not tight you can get some resonance. I got a good buzz out of mine if I did not have it mounted right.

[rmalbers]

Re: Panasonic sc tnpa5081 rebuild

It looks like I've got a bad SD and SU card. I thought they were ok but I discovered I was measuring them wrong when doing the resistance measurements. I was looking at the Panasonic 2010 -FHD Plasma TV troubleshooting Handbook and on slide 43 they talk about 'using VF-Ground' as the reference when doing the resistance measurement (I was using chassis ground). I got different results that way with VFO showing short on both boards. I just discovered this so I'm going to 'review' it some more but I thought I would get this out here for others. (Maybe everyone was doing it that way and I'm the only one who missed it, LOL!)

[svc]

Re: Panasonic sc tnpa5081 rebuild

Forgive the noob questions...I've seen a lot of references to "buffers" throughout Panasonic posts and I'm wondering which boards that refers to? And what is the diagnostic for one to be considered bad?

Thanks in advance!

[rmalbers]

Re: Panasonic sc tnpa5081 rebuild

It is the SU and SD cards (at least on p54G25). Download the doc (google it) that I referred to in the previous post and all the measurements are in it on slide 43, all the test points and readings are listed. (at least for that version of panny)

[svc]

Re: Panasonic sc tnpa5081 rebuild

Thanks! I have a slight issue with mine now that I'm into the document, but its beyond the scope of this thread, so I'm off to start a new one...