Panasonic sc tnpa5081 rebuild

[olda007]

Re: Panasonic sc tnpa5081 rebuild

Thank you for your reply tw2005.You are absolutely right.
In AY version is placed IC564 (smd code H2 - AND gate).Output signal from IC564 is marked AA_SEL2 and via SC46(pin1) and on SD board via opto PC904 and IC901 (marked c14 - inverter) delivered to buffers.AA_SEL2 I measured only on SD board.SU board is powered by a signal AA_SEL via pin 9 SC46.
In AW version, the circuit IC564 is missing.
And the second difference I've found is 10 components placed right below the jumper SC50. R819,R820,R818,R919,R799,R798,D792,C797,IC792,IC793.
There are no these components in AY version,only in AW.
I try to desolder 10 components from AW and solder IC564.

[olda007]

Re: Panasonic sc tnpa5081 rebuild

No need to desolder R819,R820,R818,R919,R799,R798,D792,C797,IC792,IC793,because R915 on Sd board not placed from pin 7 SD42.But must be placed R720-22R near connector SC46.So changing version AW to AY is easy.Solder IC564(looks like TC7SH08FU-Toshiba,marked H2) and solder R720-22R from output IC564 to pin 1 SC46.TV works with full screen!

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

No need to desolder R819,R820,R818,R919,R799,R798,D792,C797,IC792,IC793,because R915 on Sd board not placed from pin 7 SD42.But must be placed R720-22R near connector SC46.So changing version AW to AY is easy.Solder IC564(looks like TC7SH08FU-Toshiba,marked H2) and solder R720-22R from output IC564 to pin 1 SC46.TV works with full screen!

Nice

[11alon11@gmail.com]

Re: Panasonic sc tnpa5081 rebuild

this is what was replaced on the TNPA5105 jumper 50 no blinks

R 401 & 402
D451 & 490 & 491 & 618 & 652
D721
Q501 & 521 & 551
Q401 & 402
IC724
Q661
Q601 & 660
Ic501 & 521
Q451
Q421 & 422
Zener Diodes 871 and 872

the picture is noisy and low in brightness both when I display the menu and picture from HDMI

I was able to get a loaner SC board and the picture is perfect using the loaner. any ideas
attached is the bad picture. (I did cut part of the picture as it did show a reflection of me)

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

this is what was replaced on the TNPA5105 jumper 50 no blinks

R 401 & 402
D451 & 490 & 491 & 618 & 652
D721
Q501 & 521 & 551
Q401 & 402
IC724
Q661
Q601 & 660
Ic501 & 521
Q451
Q421 & 422
Zener Diodes 871 and 872

the picture is noisy and low in brightness both when I display the menu and picture from HDMI

I was able to get a loaner SC board and the picture is perfect using the loaner. any ideas
attached is the bad picture. (I did cut part of the picture as it did show a reflection of me)

well, you must be close. Did you check any of the resistors around ic521? R521,522,506. 100 ohm x 2 and a 10ohm. If ic521 was shorted and Q521 shorted fair chance the 10 ohm could be dead

[11alon11@gmail.com]

well, you must be close. Did you check any of the resistors around ic521? R521,522,506. 100 ohm x 2 and a 10ohm. If ic521 was shorted and Q521 shorted fair chance the 10 ohm could be dead

I did check resistors before and again today and thy are all good. what I am puzzled is why did Zener 871 and 872 go on this board. before I replaced them I did get a 6 blink code. I am at a lost at this problem. any other idea?

[rockit711]

Re: Panasonic sc tnpa5081 rebuild

So after my last foray into trying to rebuild one of these I thought I would try one of the other dead boards I had gotten my hands on (this one had the "tradiditonal" IC773/Q661 failure). I was very careful to go over everything a few times.

Thought I had caught everything failed, plugged it in and a bit of a whine and then 7 blinks (LED comes on OK then slowly fades away after 7 blinks).

assumed I had blown everything again, but after a thorough testing everything seems fine except for PC461 which is ~shorted (16ohm)pins5-8 (VAD+5V - VAD).

Swapped PC 461 out with a new one thinking that maybe I had missed it or it was on the edge last time and again whine and 7 blinks.

PC461 is fried again..

as far as I can tell that is it for failed parts. IC773 and 771 look good measurement wise(and I swapped these out anyway before trying again).

Any suggestions?

I'm a bit stumped TBH, looking at the schematics I'm struggling to come up with a reason how PC461 can fry and leave everything else intact.

[paulstef]

Re: Panasonic sc tnpa5081 rebuild

I've highlighted ones here which stuffed me up trying to test in cct.


D16451 B0ECKP000055 DIODE 1 ROHM , RF101L4S 400V 1A SHORT
D16482 B0FACP000003 DIODE 1 RFN25TM4SWSHORT
Q16452 B1JAEP000012 TRANSISTOR 1 GT45G128SHORT
D16702 B0ACCJ000048 DIODE 1 MA2J11100L 80v 100ma switching diode?
IC16521 C0ZBZ0001708 IC 1 M81737FP
IC16561 C0JBAU000088 IC 1 PAVCTH c541 buffer ic
IC16562 C0JBAU000088 IC 1 PAVCTH c541 buffer ic
IC16563 C0JBAB000916 IC 1 c14 INVERTER
IC16691 C0JBAC000363 IC 1 TC7SH00FU(TE85L,J
IC16724 C0CBADE00049 IC 1 BA178M05FP-E2
IC16771 C0CBADC00072 IC 1 78L05L, TA78L05F
IC16773 C0JBAB000715 IC 1 Toshiba TC7SH14F, marking HA, Schmitt NOT

PC16461 B3PBE0000054 IC 1 PS9856-2-F3-AX
Q16402 DG3D5020CSLW TRANSISTOR 1 DG3D5020
Q16403 DG3D5020CSLW TRANSISTOR 1 DG3D5020
Q16421 DG3D4020CSRP TRANSISTOR 1 DG3D4020
Q16422 DG3D4020CSRP TRANSISTOR 1 DG3D4020
Q16521 B1HFPFA00001 TRANSISTOR 1 CPH5524-TL-E
Q16551 B1HFPFA00001 TRANSISTOR 1 CPH5524-TL-E
Q16621 B1JADN000009 TRANSISTOR 1 GT30F125
Q16622 B1JADN000009 TRANSISTOR 1 GT30F125
Q16647 B1CBGD000001 FET 1 2SK3018T106,2n7002
Q16661 B1JAER000010 TRANSISTOR 1 RJP63F3A
Q16701 B1ADCN000007 TRANSISTOR 1 MMBTA92
Q16702 B1ABCF000231 TRANSISTOR 1 2PD601ART,215, 2SD0601A0L
Q16818 B1CBGD000001 FET 1 2SK3018T106,2n7002
R16452 D0GF5R6JA047 M 5.6 OHM,J, 1/3W
R16521 ERJ6GEYJ101V M 100 OHM,J,1/8W 1
R16522 ERJ6GEYJ101V M 100 OHM,J,1/8W 1
R16551 D0GD100JA059 M 10 OHM,J,1/4W 1
R16707 ERJ6GEYG392 M 3.9KOHM,J,1/8W 1

Just wanted to say thanks. very useful post

[t-echnics]

Re: Panasonic sc tnpa5081 rebuild

Hi folks,
I got a faulty TNPA5081AY.
D790 measuring is shorted.
What could be dead, too?
No visible defects or smells.
Just 10 blinks and no 15V if SC board is connected.
(P-board was already replaced)

Can anybody give me some hints?
What diode could be used for D790 - I do not find it in the part list of the service manual...

Bye,
Ralf

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Hi folks,
I got a faulty TNPA5081AY.
D790 measuring is shorted.
What could be dead, too?
No visible defects or smells.
Just 10 blinks and no 15V if SC board is connected.
(P-board was already replaced)

Can anybody give me some hints?
What diode could be used for D790 - I do not find it in the part list of the service manual...

Bye,
Ralf

Hints, seriously you have 428 replies to read plus a host of other threads potentially on the same board, plus manuals and schematics.

Now although all my work is based on the 2D model boards and yours being 3D there will be some variation but most should still apply.

My hints are:

Write down the common parts noted to fail,
get the manual, read the schematics, identify the cct variations and check similar areas,

D790 is shorted because the 15V line is shorted which you already mentioned. It won't be the diode(unlikely) Most likely will be the IGBT driver IC521(ic16521). I expect IGBTs shorted, diodes, SMD transistors, SMD ICs, maybe burnt resistors to be bad. Remove the IGBTs first then recheck the diodes, watch out for 30F125 not dead short but low ohms say 2-300 ohms, that is also failure or just replace.

I've put enough into this board, someone else can pick up the torch.

report back what you find, don't take a pot shot at doing a couple of bits and power up because it will all go bang and do twice as much damage.

If you can find a smashed tv , that may be another way of getting it going again, salvaging boards.

[t-echnics]

Re: Panasonic sc tnpa5081 rebuild

D790 is shorted because the 15V line is shorted which you already mentioned. It won't be the diode(unlikely) Most likely will be the IGBT driver IC521(ic16521). I expect IGBTs shorted, diodes, SMD transistors, SMD ICs, maybe burnt resistors to be bad. Remove the IGBTs first then recheck the diodes, watch out for 30F125 not dead short but low ohms say 2-300 ohms, that is also failure or just replace.

I just figured out a bunch of shorted parts in that area of IC521 - as you described it. I think it´s too much effort getting and replacing the parts.
I think I´m going to watch out for a replacement board...

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

I just figured out a bunch of shorted parts in that area of IC521 - as you described it. I think it´s too much effort getting and replacing the parts.
I think I´m going to watch out for a replacement board...

It's a bit of work for sure. maybe someone rebuilds them in Germany, prices for a used board, absurd these days. I got a couple, postage probably insane from here.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

This board will work AK and AY both fitted to the 50"3D models

https://www.ebay.de/itm/Panasonic-50...QAAOSwi8VZSaqb

[t-echnics]

Re: Panasonic sc tnpa5081 rebuild

This board will work AK and AY both fitted to the 50"3D models

What´s the difference of these two boards?

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

What´s the difference of these two boards?

I believe a single capacitor. See if you can find it. , near the 3 large green caps

[t-echnics]

Re: Panasonic sc tnpa5081 rebuild

I believe a single capacitor. See if you can find it. , near the 3 large green caps

Found it - at least C461 is missing in AK version.
Unfortunately some days ago I missed to buy some PCBs of a broken TV including TNPA5081AY, which I should have bought - but at this time, I did not know I am going to need it...
So I am going to wait, if I get another chance.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Found it - at least C461 is missing in AK version.
Unfortunately some days ago I missed to buy some PCBs of a broken TV including TNPA5081AY, which I should have bought - but at this time, I did not know I am going to need it...
So I am going to wait, if I get another chance.

My wife often wonders why I buy broken bits when nothing is broken. Opportunities are rare and the older they get the rarer they become. anyone who enjoys these Plasmas should grab a smashed TV or two and stock up. I'd keep an eye on those boards as they seem cheap in comparison or you may end up with no opportunity. Obviously you have other TV to watch.

I have the V20, accumalated quite a stock, finally got my hands on the VT, mainboard failed under heat, got lucky picked up a smashed one, so main plus spares and snagged another cracked one, another set of spares.

Personally I think the VT panel is more crisp than the V20.

good luck with it

[t-echnics]

My wife often wonders why I buy broken bits when nothing is broken.

Same as mine ;-)
Actually I got this TV with this failure for free - I already own two smaller Plasmas from Panasonic and really like their colors.
So I can wait to get some spare parts, but it's really a shame I did not get the other smashed one...

Thanks for your help!

[t-echnics]

This board will work AK and AY both fitted to the 50"3D models

Sorry to bother you again.
Could I also use a AH board, if I replace the big caps and coils which are obviously different or are there any other differences?

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Sorry to bother you again.
Could I also use a AH board, if I replace the big caps and coils which are obviously different or are there any other differences?

You only have the two options I gave or will be a genius effort to reconstruct the AH to be AY because the circuitry in entirely different in that left hand congested area where the SC20 ribbon is.