Panasonic sc tnpa5081 rebuild

[Alastair E]

Re: Panasonic sc tnpa5081 rebuild

Would it be worth wiring the V-SUS via a 150W lamp?

May prevent more failures of new devices.....

I did this recently with a Pan board that had blown a load of silicon....

[tw2005]

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

Generally this is the deal with Q661.

Q661, Q701,702,818, IC773, D702 and IC771 must be good.
If you have any old boards like buffers or SS from this time you may be able to recycle one but it's damn small

I had the Q621, Q622, (D642 & D641-RF2001) failure on that last board i did, for me the 30f125 survived, only 1 Rf2001TM3S was shorted but shorts those 4 in cct.

I would check D451, you really have to rechecked everything

How were Q16421,422? They commonly fail short too

Q660, I'm yet to strike one bad

All I can suggest is rebuild The Q661 list or remove q661, check resistance IC771 vout -gnd, but also Vin -gnd and Vout-Vin, that reg can fail(has) and that will definitely blow Q661.

IC501 I've never had an issue

IC521 definitely

You may have extra damage now. How is R707?

maybe when you think it's ready come back and I'll run through some check points I know but I have not had much luck coaching of late

Do you have a good board to compare too?

[Glitcher]

Re: Panasonic sc tnpa5081 rebuild

May be awhile til I get more parts, I ordered a bunch of dg402/502, that finally came in after 2 months.. I don't have a good board to compare to. With all three of my boards I never had a bad r707. They always read 3.9k ohms if I remember right.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

May be awhile til I get more parts, I ordered a bunch of dg402/502, that finally came in after 2 months.. I don't have a good board to compare to. With all three of my boards I never had a bad r707. They always read 3.9k ohms if I remember right.

For sure, but how is it now? I have had one blow on a repair attempt. 2 months! Where from?

so you have 3 bad boards but no success yet on any? Is that the deal?

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Looking at your list, I'm thinking D702, ic771. Do you want some measurements for good in cct?

[Glitcher]

Re: Panasonic sc tnpa5081 rebuild

I ordered the parts from aliexpress, and had shipping problems.. I have 3 boards so far, 2 of which are doing the same thing (Q661 blows taking with it 30f125 and rf2001 on both) and the third is beyond repair, I replaced everything on that one and it just ended up blowing every IGBT again so I'm going to not bother with that one anytime sooon...

R707 is reading 3.89K ohms.
D702 in diode mode reads 1.671 and 0.601.

I think I measured IC771 with a known good one, but D702 I'm not sure if bad.

Hm I'm just looking over the board now, seems do have extra damage, I have more shorted parts than I thought... Q402, Q403, Q421, Q422 are reading dead shorted in there now.

So I just replaced replaced Q422, Q421, Q402, Q403.
Q622 and Q621 aren't dead shorted(i'll need to replace them anyway to be safe) but D642 and D641 are reading lower resistances than normal so I'll assume they are bad. I removed all four of them for now.


So I also just removed Q661 and measured IC771. In diode mode, gnd-vout measures 0.107 (both directions), gnd-vin measures 0.241 (both directions), and vin-vout measures 0.301 in both direction. So seems something else is bad now... removed it from circuit and the pads are measuring the same.


---also just found Q702 shorted now.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

I ordered the parts from aliexpress, and had shipping problems.. I have 3 boards so far, 2 of which are doing the same thing (Q661 blows taking with it 30f125 and rf2001 on both) and the third is beyond repair, I replaced everything on that one and it just ended up blowing every IGBT again so I'm going to not bother with that one anytime sooon...

R707 is reading 3.89K ohms.
D702 in diode mode reads 1.671 and 0.601.

I think I measured IC771 with a known good one, but D702 I'm not sure if bad.

Hm I'm just looking over the board now, seems do have extra damage, I have more shorted parts than I thought... Q402, Q403, Q421, Q422 are reading dead shorted in there now.

So I just replaced replaced Q422, Q421, Q402, Q403.
Q622 and Q621 aren't dead shorted(i'll need to replace them anyway to be safe) but D642 and D641 are reading lower resistances than normal so I'll assume they are bad. I removed all four of them for now.


So I also just removed Q661 and measured IC771. In diode mode, gnd-vout measures 0.107 (both directions), gnd-vin measures 0.241 (both directions), and vin-vout measures 0.301 in both direction. So seems something else is bad now... removed it from circuit and the pads are measuring the same.


---also just found Q702 shorted now.

R707 is reading 3.89K ohms. GOOD

D702 in diode mode reads 1.671 and 0.601.VERY CLOSE TO MINE IN CCT

I think I measured IC771 with a known good one, but D702 I'm not sure if bad.

seems do have extra damage, I have more shorted parts than I thought... Q402, Q403, Q421, Q422 are reading dead shorted in there now.
(how confident are you they were ok in the start? these are usually always dead when I've worked on these

So I just replaced replaced Q422, Q421, Q402, Q403.
Q622 and Q621 aren't dead shorted(i'll need to replace them anyway to be safe)
SO I ASSUME WE'RE TALKING DG402 x 2, DG502 x 2, 30F125 x 2

D642 and D641 are reading lower resistances than normal so I'll assume they are bad. SHOULD BE EASY ENOUGH USING DIODE TO CHECK, IN CCT 0.342 I HAVE HAD THESE FAIL AFTER A FAILED REPAIR(LAST BOARD ACTUALLY)DEAD SHORT BUT YOU MAY FIND WITH THE 30F125 REMOVED THEY MAY BE OK

So I also just removed Q661 and measured IC771. In diode mode, gnd-vout measures 0.107 (both directions),BAD, I ASSUME IC773 WAS STILL IN CCT? gnd-vin measures 0.241 (both directions) THAT'S NOT LOOKING GOOD I GET 0.482, 0.600, and vin-vout measures 0.301 in both direction ALSO NOT GOOD, 0.586, 0.956
So seems something else is bad now... removed it from circuit and the pads are measuring the same.TRY either REMOVING IC773, or pc561 & RETEST, IF THERE'S STILL AN ISSUE THEN IT'S the other bit. pins 5 - 8 of the opto is on the same 5v supply out from ic771

---also just found Q702 shorted now IF IT WERE ME I'D ERR ON THE SIDE OF CAUTION, I'D BE DOING Q661,701,702,818, IC773, IC771(I'm also thinking real chance the opto is blown too). ALSO I'D START THE FAULT FINDING FROM SCRATCH IGNORING WHAT WAS REPLACED GOOD OR BAD AND TAKE THE APPROACH YOU'RE REPAIRING THIS FROM SCRATCH. TOO EASY TO SKIP THINGS THAT WERE OK IN THE BEGINNING BUT NOW POSSIBLY BAD, DID YOU CHECK D451, Q452?

ALSO Q521,551 (3-3.5MEG) PLEASE MEASURE RESISTANCE AS PER IMAGE.

I'D PREFER YOU GIVE ME RESISTANCES . I KNOW THEM OFF THE TOP OF MY HEAD FOR THE FOLLOWING WHEN YOU GET SORTED.

ACROSS C561(5.6K),
TP82-GND (1250-1400 OHMS)(TRY BOTH DIRECTIONS)
IC771 Vout-GND must be 5.7-6.1K in cct.

Try to avoid the urge to power this up until I get a chance to confirm stuff with you(please)

[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.

Just updating this board is still running fine. been in my TV since repair for 3 months now, all parts were from UTSOURCE and it's the main TV used every day

[stryacker]

Re: Panasonic sc tnpa5081 rebuild

personal hello.
I need help on the board tnpa5081af.
made repairs exchanging components 30 + or -.
now the tv is calling but does not appear sound and I have no video.
I like the post tw2005.
personal excuse the translation because I am Brazilian, and I am using translator ok.
if they can help me I will be very grateful

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

personal hello.
I need help on the board tnpa5081af.
made repairs exchanging components 30 + or -.
now the tv is calling but does not appear sound and I have no video.
I like the post tw2005.
personal excuse the translation because I am Brazilian, and I am using translator ok.
if they can help me I will be very grateful

I've found it very hard to help people with these even though I manage to fix them.

you would have to list what parts have been replaced.

30 or so parts replaced is not the norm, closer to about 13 parts.

The translator is not making the message clear.

"now the tv is calling but does not appear sound and I have no video."

not sure if this is saying TV is On, sound but no picture or what symptoms you have?

is the Tv turning on and staying on(no error blinks) but you have no image but the screen appears to be on?

any chance you can upload a clear image of the board (component side ) for me to see?

[stryacker]

Re: Panasonic sc tnpa5081 rebuild

I've found it very hard to help people with these even though I manage to fix them.

you would have to list what parts have been replaced.

30 or so parts replaced is not the norm, closer to about 13 parts.

The translator is not making the message clear.

"now the tv is calling but does not appear sound and I have no video."

not sure if this is saying TV is On, sound but no picture or what symptoms you have?

is the Tv turning on and staying on(no error blinks) but you have no image but the screen appears to be on?

any chance you can upload a clear image of the board (component side ) for me to see?

Hello sorry for the bad translation.
all the transistors and diodes were exchanged.
Q421, Q422
D421, D422
Q621, Q622
D641, D642
Q601 Q660 And were good not changed!
Q661
Q401, Q402
D401, D402
Q452, D452, D451
Q441, D462
IC773 was in short was exchanged for the same HA
IC771 was exchanged good
IC691
IC562
IC774
IC521
Q551
Q521
Q810
Q701
2SK3018 all been replaced.
turn on the tv looks good and I have no video or audio
I have 50v in tpvscn and tpsc1
very strange.
now the tv stopped showing up the brightness in the image, but I believe That Is not the screen.
When moved the flat cables had very clear vertical stripes.
green LED lit without blinking.
Thanks for listening.

[stryacker]

Re: Panasonic sc tnpa5081 rebuild

the TV is not switched off in the control before could turn it off.
now not go stand-by.

my head it is on fire

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

sounds like the SC board is working but you have other issues like bad A board if you have no control of the TV. vertical stripes is not encouraging either, could be A board or panel but without some images (photographs) we have no idea what we're looking at here.

try and get some photos up

[stryacker]

Re: Panasonic sc tnpa5081 rebuild

The tracks are on the screen because they were poor contact.
When I cleaned the contacts back to normal.
This is common when a fault in the connector.
I realized that the Plate A ic stopped heat.
When he was hot on the screen appeared brightness and obeyed on off.

[stryacker]

Re: Panasonic sc tnpa5081 rebuild

I believe is A board
I will make a reflow chipset to see if it is defective bga.
I'll need luck now
PSU Q201 Q202 plate short changed by equivalent.
2SK352 are identical.
in sc board not found the GT45G128 here in Brazil can not find anywhere.
GT45G128 = RJP43F4A. and works perfect.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

I believe is A board
I will make a reflow chipset to see if it is defective bga.
I'll need luck now
PSU Q201 Q202 plate short changed by equivalent.
2SK352 are identical.
in sc board not found the GT45G128 here in Brazil can not find anywhere.
GT45G128 = RJP43F4A. and works perfect.

45g128 is easy to find on Ebay or China. I had to import everything but I like your creativity.

I've wondered for a while now substituting other IGBTs instead of getting the exact same.

anyway of you putting photograph up?

[stryacker]

Re: Panasonic sc tnpa5081 rebuild

I sent photos as promised..

[stryacker]

Re: Panasonic sc tnpa5081 rebuild

I have a doubt.
now TV features 13 LED blinks
after 5 minutes, and turns off alone.
and blinks 13 times.
checked one 47k resistor that is with 3k, the connector pin 11 A7.
what is this?




pin 11 of the connector A-board A7

[stryacker]

Re: Panasonic sc tnpa5081 rebuild

I sent photos as promised..

I think I overdid

[stryacker]

Re: Panasonic sc tnpa5081 rebuild

I think I overdid

solved staff!!
I reball in ddr3 memory of the motherboard and she returned to work