Panasonic sc tnpa5081 rebuild

[RayOMG]

Re: Panasonic sc tnpa5081 rebuild

Have a preliminary list so far, seems to be most of the long list of parts.
One extra faulty part is IC691

Found dead:

D16451
D16482
D16702
Q16452
IC16521
IC15771
IC16773
Q16402
Q16403
Q16421
Q16422
Q16521
Q16551
Q16647
Q16661
Q16701
Q16702
Q16818
R16521
R16522
R16707

IC16691

still testing buffers IC16561 and IC16562 not sure if they are OK befor I plug the board in and all my work goes up in smoke!!!

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Have a preliminary list so far, seems to be most of the long list of parts.
One extra faulty part is IC691

Found dead:

D16451
D16482
D16702
Q16452
IC16521
IC15771
IC16773
Q16402
Q16403
Q16421
Q16422
Q16521
Q16551
Q16647
Q16661
Q16701
Q16702
Q16818
R16521
R16522
R16707

IC16691

still testing buffers IC16561 and IC16562 not sure if they are OK befor I plug the board in and all my work goes up in smoke!!!

D16451 RF101L4S 400V 1A
D16482 RFN25TM4SW
D16702 MA2J11100L 80v 100ma
Q16452 GT45G128
IC16521 M81737FP
IC15771 78L05L, TA78L05F
IC16773 TC7SH14F, marking HA, Schmitt NOT
Q16402 DG3D5020
Q16403 DG3D5020
Q16421 DG3D4020
Q16422 DG3D4020
Q16521 CPH5524-TL-E
Q16551 CPH5524-TL-E
Q16647 2SK3018T106,2n7002
Q16661 RJP63F3A
Q16701 MMBTA92
Q16702 2PD601ART,215, 2SD0601A0L
Q16818 2SK3018T106,2n7002
R16521 100 OHM,J,1/8W 1
R16522 100 OHM,J,1/8W 1
R16707 3.9KOHM,J,1/8W 1
IC16691 TC7SH00FU(TE85L,J

IC16561 TC74VHC541FK
IC16562 TC74VHC541FK

wow, yes that is a big one. is this the first repair attempt or has someone tried replacing just the IGBTs and blew it up a second time?

IC561,562, real chance that's taken a hit with that list. I've had one go low ohms across vcc and gnd but still can be faulty. I don't think they'll cause smoke but it won't work. If they are dragging the 5V line down then yes they probably will as that will affect the schmitt inverter and most likely pop Q661 and then a bunch of others.

If you have spares, I'd replace them otherwise if you have other scrap boards from 2010, you can find them on C boards, SS and other SC. Bloody small and i have not found a sub for them.

You better check out PC16461 across pins 5-8 if all that is blown. 5.8k I get in cct. I've had one go short , and one go low at 800ohms. Obviously any other shorted parts on that 5v line would need to be removed. I've had one shorted but cleared and was ok once I removed the shorted schmitt inverter.

Having the 3.9k resistor bad, I've only struck that on 2 failed repairs when I missed q16701, thats where a bang and flash of light exits the resistor

[RayOMG]

Re: Panasonic sc tnpa5081 rebuild

Also found IC16562, -one of the buffer ICs faulty, these ICs actually get power from the A-board (main board)
PC16461 (opto coupler) was also low, so replaced that.
Couldnt find anything else wrong and plugged it in to the set with SD and SU removed and SC50 shorted.
Well, didnt even make a noise, blinking 7 times after few secs and most of the big transistors dead again.
This board had blown the face off one of the parts when I first checked the TV, but no parts had been replaced.
I have given up on this board now, as its not worth spending any more time on it. replaced 24 parts in total on this board

The second board I was working on for a 54" set didnt work either in the 50" set but at least didnt blow all my work up again,
I will have a go later on but right now I think there are too many variables to these boards blowing up in random areas and not knowing the cause is a major problem

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Also found IC16562, -one of the buffer ICs faulty, these ICs actually get power from the A-board (main board)
PC16461 (opto coupler) was also low, so replaced that.
Couldnt find anything else wrong and plugged it in to the set with SD and SU removed and SC50 shorted.
Well, didnt even make a noise, blinking 7 times after few secs and most of the big transistors dead again.
This board had blown the face off one of the parts when I first checked the TV, but no parts had been replaced.
I have given up on this board now, as its not worth spending any more time on it. replaced 24 parts in total on this board

The second board I was working on for a 54" set didnt work either in the 50" set but at least didnt blow all my work up again,
I will have a go later on but right now I think there are too many variables to these boards blowing up in random areas and not knowing the cause is a major problem

Not sure if there is a cause you can pin it on . The TV I have was about 18 months old, SC shorted at 2500hrs, I replaced the board with a US AP version, 7000hrs later still working.

Just swapped over the SC for my original mule board to see how it goes over an extended time.

If you replaced all those I'm surprised it blew up, one thing I do see is no 30F125 IGBTs in the list. If all those others were blown, i would expect they would have been shorted too.

any chance you missed those?

I've repaired 4, yet to have one that did not have at least 1 30f125 dead.

What model TVs are these boards from? P50V20A & P54V20A?

[wveno49]

Re: Panasonic sc tnpa5081 rebuild

Hi All,

I have a Panasonic TC-P50VT25 tv. The other night I had a pop from the upper right rear corner of the TV and it went dead. I found C-460 blown on the board identified as TNPA5081 Rev K.

I need to identify the value of that cap can any one help? Also any ideas as to what may have taken it out or is a just a bad Cap?

Walt

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

got a picture to post? So it rev AK. I have not touched any 3D model boards so not 100% if the repair is the same as some of the cct is different but might be able towork it out. I have an AK here so I'll look or the service manual parts breakdown will tell us. Standby

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Actually I have AY but same board really, that's really unusual to find this blown?, it's a 630V 820pf cap, type unsure but I'm really curious to get a view of what you see.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Oh, no it won't be just a cap issue. The pop I would expect would be the transistors popping. Start with Q661, that one always shortsand others etc etc

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

I'm thinking something like this

http://www.digikey.com.au/product-se...=0&pageSize=25

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

If you want the real McCoy, this is the part number (Panasonic number who knows the OEM brand)

https://www.partstore.com/Part/Matsu...1A002/New.aspx

found this description with a google

CERAMIC CAPACITOR MULTI LAYER F1E2J821A002 (SPARE PARTS FOR PANASONIC PLASMA DISPLAY).

[wveno49]

Re: Panasonic sc tnpa5081 rebuild

tw2005 thanks for the help

Q661 appears to ok and I have attached a pic of the blown cap (C-460).

wveno49

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Wow. What can I say, looking toasty. No idea on that one.

[tom66]

Re: Panasonic sc tnpa5081 rebuild

Will be ~100pF capacitor for EMI filtering... can be safely removed for testing but should be installed for proper repair.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Will be ~100pF capacitor for EMI filtering... can be safely removed for testing but should be installed for proper repair.

I managed to ID it and they're 630V 820pf .

As far as this board goes, all I could suggest is check all IGBTs and diodes on the heatsinks for shorts,

Measure the resistance for the 5V & 15V lines in to the Sc board and post that info.

How many blinks 7? I'd check buffer boards too.

Like i said, this is the first post of something like this so you'll be teaching us here on this one

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Just fixed another one. Had someone track me down so did one on exchange.

So far so good, I was not sure about doing this mainly because of the chinese parts but we'll see. Not sure how long I should run it, maybe a week or 2.

SC2 was not dead short but low enough to trigger a SOS4

IC16521 M81737FP, FET DRIVER (had an exit wound)
IC16773 TC7SH14F, schmitt inverter ic (can use SN74AHC1G14DBVTG4) (shorted)
Q702 2PD601ART NXP (C3 W), (shorted)
Q661 RJP63F3A (shorted)
Q622 GT30F125(R) (not short but low ohms got 0.190 in diode, normally around 0.9 -1.00 in cct) The other was ok. Have not seen this before but have found one survives in a pair.
Q402,DG502LW (shorted) other was ok.
Q421,422 (shorted)
Q452 GT45G128 (shorted)
D482 RFN25TM4SW (shorted)
D451 RF101L4S (shorted)

Q701 MMBTA92 seemed ok but replaced
Q818 2SK3018 also not shorted but replaced

Successful repair first go. 13 parts replaced

I have not had one yet that that did not need at least one 30F125 and nearly brushed over them with no short. Being suspicious I grabbed another board just to check and big discrepancy. very lucky, so easy to be complacent.

Love to see other repair reports here.

Sorry for the bad photo and missed the FET driver IC in the shot.

TV shot is with it running the repaired board.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild PART NUMBER CORRECTION

Was helping somone with this board and had to check a part they'd used as a sub for D451.

Well, I've discovered along the way that I misread the smd mark as 88, they are 83, by ROHM

Not a bad error because what I quoted was slighly higher surge rating.

D451 = B0ECKP000055 = RF071L4S = 400V 1A, marking 83

Pretty sure I've quoted RF101L4S , 400V 1A, marking 88, it has a higher surge current rating at 25A as opposed to 15A so all good to use

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Board #6 Repaired TNPA5081AF. Again someone tracked me down via here so did the exchange thing.

This is the first board with the different looking DG402RP & DG502LW chinese parts which I'm unsure about. they're the same as what you see in a lot of Ebay kits, so again I'll give it a good run.

SC2 was not dead short.

I thought I'd try something different and see if i was good enough to determine out of Q701,702 & 818 were bad. Of those none were showing dead short. Normally Q702 is.

After looking closely it was low in ohms about 200. Q701 again seemed ok but then one side did not measure up possibly open cct, replaced that

Q818, the one i hate as it's hard to really know, did compare well in cct so left it(usually now i just replace)

So initial list is

IC16521 M81737FP, FET DRIVER , 15v line was pretty close so seemed it may be ok but when i did resistance checks on Q551 and Q521 they has low ohms, normally over 3 meg. It was the FET driver IC

IC16773 TC7SH14F, schmitt inverter ic (can use SN74AHC1G14DBVTG4) (shorted)
Q702 2PD601ART NXP (C3 W), (low ohms)

Q661 RJP63F3A (shorted)

Q621,622 GT30F125(R) (not short but low ohms got 0.190 in diode, normally
around 0.9 -1.00 in cct) replaced both

Q401,402,DG502LW (shorted)

Q421,422 DG402RP (shorted)

Q452 GT45G128 (shorted)

D482 RFN25TM4SW (shorted)

D451 RF101L4S (was ok)

Q701 MMBTA92 ( replaced)

Q818 2SK3018 (left)

END RESULT, FAIL - 7 blinks

I blame this on Q818

NEW LIST - 2ND GO


q701,702, IC773, Q621,622,Q401,402,Q421,422, Q452, D482,IC521 all survived.

This is what did not including new parts.

Q661, d641,642(never had to replace these before), q818 was replaced, D451 has now failed, i found that after every else was right, panel energised then 6 blink

So it's the same lesson, it's best to replace Q701,702,818,IC773, Q661, then check ic771 resistance vout -gnd, must be 5.7-6.1k, if lower like 4-5k then check d702.

check all over heatsink parts for shorts,replace where applicable, recheck diodes associated, replace Q621,622, check d451, replace the FET driver ic521.

check Q521,551, width ways, opposing pins at both ends, usually over 3meg

After this, recheck resistance for P5V = 5.6k, P15V= 1240 or more, vad+5v(IC771 5v out - gnd) 5.7-6.1k

the key to this is getting Q661 and the inverter cct 100%, use the manuals and schematics.

[Glitcher]

Re: Panasonic sc tnpa5081 rebuild

I've been having a hell of a time with this board. I have 3 of them now, all AF I think. Checked and replaced every suspect part on the list and Q661 still pops... Along with shorted 30f125 and sometimes rf5001...

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

I've been having a hell of a time with this board. I have 3 of them now, all AF I think. Checked and replaced every suspect part on the list and Q661 still pops... Along with shorted 30f125 and sometimes rf5001...

Failed repair can be interesting. you'd have to pick the board you have issues and if you kept a list of of the parts replaced each time list them. Also what part went in place of when repaired. I think you mean 2001 for the diode but what suffix is after that for the bits you are using, they're not all the same.

Not quite sure why people are having trouble following the info, must be one thing that's missed.

[Glitcher]

Re: Panasonic sc tnpa5081 rebuild

Ah yes, rf2001 that's right. 30f125 were suffixed "R" and I replaced them with the same.

All the parts replaced initially were (Rf2001 was fine initially),
IGBTs and diodes on heatsinks: Q661, Q660, Q402, Q403, Q421, Q422, Q452, D482, Q621-30f125, Q622-30f125 .

Surface Mount: Q702, Q701, Q818, IC773, IC724, Q551, Q521, IC521, D451,

Plugged it in, pop goes Q661, and Q621, Q622-30f125.

The only part I didn't replace was D702 since I can't seem to source it anywhere, but ohming it out seemed okay, wasn't dead shorted at least.

Looked around again, realized I missed IC501, replaced that, Q661, Q621 & Q622
Checked everything else. seems goood

Plugged it in, Q661 pops again, this time along with Q621, Q622, (D642 & D641-RF2001)
Replaced all those popped again, checked everything else seemed fine.

PLug it in hoping it was just the RF2001 I missed. and pop again... same blown parts as above...


Just lost now... Seems the problem is mainly Q661, if there was a list of parts that should just be replaced only to prevent Q661 from blowing. But then it also takes with it 30f125 and RF2001 so not sure if that's an entire different problem