Panasonic sc tnpa5081 rebuild

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Hi, guys!

Finally back. The board just arrived after 2 months of waiting and no taxes charged. Apparently brand new, no visible burnt components or use marks


The board is slitly different from the original having only two of the three big caps (guess it's a AH and not a AF)

New:


Old:


Checked Q661 as tw2005 sugested and proved fine.
Put it back on the TV (a Pana TC-P50V20B), double checked all the connections and flat cables, fingers crossed and a deep breath.

And then...



IT WORKED!
Crispy cristal clear image as always.
Thanks so much TW2005 for all your help.

One last question: Is there any problems with the lacking capacitor? Durability maybe?

Att,
Will Santana

To be honest, I don't know but the boards are matched to the panels and why there's different versions. You'll find those caps and the two inductor coils will be different.

You could swapover those parts and check the rest of the caps for differences.

[will_santana]

Re: Panasonic sc tnpa5081 rebuild

Hi, guys!

Finally back. The board just arrived after 2 months of waiting and no taxes charged. Apparently brand new, no visible burnt components or use marks


The board is slitly different from the original having only two of the three big caps (guess it's a AH and not a AF)

New:


Old:


Checked Q661 as tw2005 sugested and proved fine.
Put it back on the TV (a Pana TC-P50V20B), double checked all the connections and flat cables, fingers crossed and a deep breath.

And then...



IT WORKED!
Crispy cristal clear image as always.
Thanks so much TW2005 for all your help.

One last question: Is there any problems with the lacking capacitor? Durability maybe?

Att,
Will Santana

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

"I chose this board as it had the "least" damage (with IC773 seemingly intact), but perhaps I would have been better going for one with shorted IC773 etc, that way at least its faults would line up with what others have done in the past."

there's a bit of logic to this. If the board has failed in a manner other than the Usual that may be a reason following my "generic" has not worked.

If you can fix a 4782, I think you can do a 5081. I've had about 50/50 luck ratio with the few 4782 boards I've played with and I find the 5081 easier but then it probably boils down to practice and familiarity.

[rockit711]

Re: Panasonic sc tnpa5081 rebuild

Yeah, funny. Not economically repairable would be more the truth. Once you invest time and effort working it out, they're quite repairable. Problem being getting real parts , virtually impossible.

Everything I've done and come across I've posted so I'd be repeating myself.

Most common failures have involved the inverter ic773, in fact 99%, may have had one ok. That usually means Q701,702, 818 can be suspect. Just replace them, it's easy to rush and not check every combination of the legs and out one of those combos comes up short. I think 818 more often than not is ok but I just replace it. Q661 always dead, rare Q660 is dead but obviously if shorted, replace. ic771 5v reg usually ok but can be bad, opto also often good, 1 or 2 i've seen bad and vcc to gnd I think pins 5-8 will be low resistance.

never had to touch ic16501 but ic16521 I would always do and often there's be a blister, that then leads to poptentially Q551, D451, Q452, D482, sometimes the R551 10 ohm can be gone as too any gate resistor on any shorted IGBT. R452, R421,422 I've done, R521,522 can also be damaged and out of spec, the drive signals from the buffer ICs at SC20 feed to there and occasionally get damaged . Nearly always DG502 and DG402 short, 30F125 can mislead and not got short but go to 200 -300 ohms and tricks people into thinking no short, good if continuity check.

Obviously you would check all diodes especially those mounted ones for short but you'd remove the usual suspect transistors first and often the diodes clear as ok.

I have no more magic information, I'm afraid. Sometimes it may be better to start afresh on another board with no attempt , with a different approach. I'll never forget how much work it was to get my first board going when I cocked it up first time.

Fixed many after it , but never gave up on it, eventually got it.

I recently hit a bad 5105 board, failed first go, failed second go, gave up, went to another 5105 virgin and fixed it first go.

have yu got a Tv needing the 5081?

Thanks for the advice, yes have a 50v20a that obviously is now short a SC. I have read through this thread a few times and checked the parts where you and others have been stumped in the past and come up blank now.

Ive pulled out Q401&2 (dg502) they both test ok out of circuit. D401 &402 also test good once out.

it looks like the only (maybe?) casualties from the try were Q661 and D641, but ill probably replace the rest on that line too (the 30F125s and the other diode) just to be safe.

the 771 is still showing 5.6kohm and the rest of the test points that have been mentioned in this thread also seem right. ive pulled out all the transistors that were mentioned that go with 773 and they were all good out of circuit too (at least with the tests that I can do). I'll swap in new ones of those anyway and the 773 and then maybe give it another going over for any freshly (or missed) failed parts and try it again:/

I still have weird readings C-E on Q401 pads, its reading OL on 600, 6k and 60k settings both ways, when I hit the 600K or higher setting it drops to 0ohm measured one way and dropping from ~6M down slowly the other way. does this on a few of the dead boards where Ive cleared the shorted IGBTS. Im not sure if that's normal or not:/, could it have to do with those big caps on VSUS charging?


do you have any advice in testing the buffers/ c14 inverter? Obviously I have a few on all the dead boards and they all seem to match up however I test them (resistances diode etc) so I suspect they are all fine (it seems like its rare to have them go?)

I have a good TNPA4782 that I fixed awhile back for a friend (following mostly this thread again as the board are very close) im using as a reference, obvioulsy it isn't 100% the same, but that's where i've been getting reference values for the components around 773 for as that part of the circuit is pretty much identical.


maybe ill look at one of the dead boards and see if one of those would be easier:/

I chose this board as it had the "least" damage (with IC773 seemingly intact), but perhaps I would have been better going for one with shorted IC773 etc, that way at least its faults would line up with what others have done in the past.

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

you could use RJP43F4A for DG402, RJP56F4A for DG502

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

I tested them out of circuit. Having read through this thread already and seen a few of your comments stating that at least one of them seems to fail every time, I thought I would do a better test on all the "big" components than simply a short circuit test in case any of them failed in a way that wouldn't show in circuit.

I did resistance C-E (from memory I got ~2.4M one way and OL the other)
then I did the "turn on test" turning the gate on with a multimeter on diode setting while measuring resistance C-E with another meter, then shorted the gate back off, I got <100k with the gate on and OL with it off (my meter only puts out max ~3.2v on diode setting so probably not quite on their turn on thresholds), these seemed consistent with the other 30F125s I had (both some ordered in from china and some off "good" SS boards I got at the same time as the SCs)


Sorry I wasn't clear(er), I wasn't expecting to get one good from several bad. Its pretty clear that wouldn't happen seeing as the dg502lw have gone on every single board.

I ordered a bunch of parts from china, got a few sets of what I anticipated needing.



I got the boards when I contacted a local repairer about repairing the board as at the time I felt it was a repair beyond my abilities (may still turn out to be!), he said they couldn't be repaired and "sold" me his collection of dead SC boards and some SS's that were supposed to be working (I didn't test them as obviously the Tv is missing the SC! but I would guess they were fine, I didn't find any shorted components on them and seeing as its almost always the SC I suspect they're good)

Yeah, funny. Not economically repairable would be more the truth. Once you invest time and effort working it out, they're quite repairable. Problem being getting real parts , virtually impossible.

Everything I've done and come across I've posted so I'd be repeating myself.

Most common failures have involved the inverter ic773, in fact 99%, may have had one ok. That usually means Q701,702, 818 can be suspect. Just replace them, it's easy to rush and not check every combination of the legs and out one of those combos comes up short. I think 818 more often than not is ok but I just replace it. Q661 always dead, rare Q660 is dead but obviously if shorted, replace. ic771 5v reg usually ok but can be bad, opto also often good, 1 or 2 i've seen bad and vcc to gnd I think pins 5-8 will be low resistance.

never had to touch ic16501 but ic16521 I would always do and often there's be a blister, that then leads to poptentially Q551, D451, Q452, D482, sometimes the R551 10 ohm can be gone as too any gate resistor on any shorted IGBT. R452, R421,422 I've done, R521,522 can also be damaged and out of spec, the drive signals from the buffer ICs at SC20 feed to there and occasionally get damaged . Nearly always DG502 and DG402 short, 30F125 can mislead and not got short but go to 200 -300 ohms and tricks people into thinking no short, good if continuity check.

Obviously you would check all diodes especially those mounted ones for short but you'd remove the usual suspect transistors first and often the diodes clear as ok.

I have no more magic information, I'm afraid. Sometimes it may be better to start afresh on another board with no attempt , with a different approach. I'll never forget how much work it was to get my first board going when I cocked it up first time.

Fixed many after it , but never gave up on it, eventually got it.

I recently hit a bad 5105 board, failed first go, failed second go, gave up, went to another 5105 virgin and fixed it first go.

have yu got a Tv needing the 5081?

[rockit711]

Re: Panasonic sc tnpa5081 rebuild

I tested them out of circuit. Having read through this thread already and seen a few of your comments stating that at least one of them seems to fail every time, I thought I would do a better test on all the "big" components than simply a short circuit test in case any of them failed in a way that wouldn't show in circuit.

I did resistance C-E (from memory I got ~2.4M one way and OL the other)
then I did the "turn on test" turning the gate on with a multimeter on diode setting while measuring resistance C-E with another meter, then shorted the gate back off, I got <100k with the gate on and OL with it off (my meter only puts out max ~3.2v on diode setting so probably not quite on their turn on thresholds), these seemed consistent with the other 30F125s I had (both some ordered in from china and some off "good" SS boards I got at the same time as the SCs)


Sorry I wasn't clear(er), I wasn't expecting to get one good from several bad. Its pretty clear that wouldn't happen seeing as the dg502lw have gone on every single board.

I ordered a bunch of parts from china, got a few sets of what I anticipated needing.



I got the boards when I contacted a local repairer about repairing the board as at the time I felt it was a repair beyond my abilities (may still turn out to be!), he said they couldn't be repaired and "sold" me his collection of dead SC boards and some SS's that were supposed to be working (I didn't test them as obviously the Tv is missing the SC! but I would guess they were fine, I didn't find any shorted components on them and seeing as its almost always the SC I suspect they're good)

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Having my first try at a TNPA5081AF board

These are the parts that I isolated as failed the first sweep:

D16451 RF101L4S 400V 1A SHORT
D16482 RFN25TM4SW SHORT
Q16452 GT45G128 SHORT
Q16402 DG3D5020CSLW SHORT
Q16403 DG3D5020CSLW SHORT
Q16421 DG3D4020CSRP SHORT
Q16422 DG3D4020CSRP SHORT
Q16551 CPH5524-TL-E SHORT
Q16661 RJP63F3A SHORT
Q16660 R5007ANX SHORT
I wasn't sure about IC16521 (M81737FP), so swapped it given Q551 and D451 had failed.

I tested all the parts usually associated with IC773 and they all looked good as far as I could test (including 773!)



so I plugged the board in. got the green LED illuminating but then went 7 blinks and it looks like Ive re-killed some stuff:

Q16661 B1JAER000010 TRANSISTOR 1 RJP63F3A dead short
D641 - dead short
D642 - seems ok diode and resistance - will probably swap anyway
(Q621 622 seem ok but I think ill swap them now just to be safe, they seemed ok out of circuit before I tested the repair, but now that D461 is shorted I think ill play it safe this time round and swap them anyway)

a few other oddities i will likely just replace:

Q16402, Q16403 DG3D5020CSLW TRANSISTOR 1 DG3D5020 - these were showing dead short in circuit, but out of circuit they test OK (~2Meg resistance one way , turn on/off with turn on test)

the dead short resistance still shows up (probably the associated diodes), but I noticed its only with the polarity one way?? If I reverse the probes I get high resistance <Mohm - think ill have to look into this one a bit further!


here were a few things that I wasnt totally sure about the first time:
PC16461 B3PBE0000054 IC 1 PS9856-2-F3-AX
It wasn't measuring shorted across 5-8 but did show ~20kohm when measured in reverse polarity (red probe on the gnd pin and black on vcc) this was causing IC771 to measure ~4kohm when measured back the other way.
was this correct? I have a number of other failed boards I bought hoping to scavenge enough parts off them, it looks like almost all of the PC461 seem to measure 20-30kohm when resistance is measured in reverse across VCC-GND but found one on another board that wasn't doing this so swapped it. perhaps I swapped in a bad one thinking the others were bad?


I was extremely careful to test the parts associated with IC773: Q701, 702, D702 q818, all appeared unfailed and functional (transistors measure appropriately for their type using diode test B-c B-e etc) I took Q701 and 702 out and measured them out of circuit and they showed good. IC773 likewise did not show any low resistances or any unexpected measurements when compared to what would be expected off schematics

Obviously with Q661 dead I suspect I missed something in the inverter circuit but having pulled out Q701 Q702 D702, Q818, R707 they all test good out of circuit, so i doubt it was one of those. The only thing I could think of was it possible the IC773 to fail open circuit, it looks like reading this thread that it seems to ALWAYS fail and always be shorted or low ohms?


any guidance would be much appreciated!

Going to be hard giving good advice now but my first question will be this.

How did you test Q621,622? what did you read? Originally before the second blow up?

Unlikely you'll make one good one from several bad.

[rockit711]

Re: Panasonic sc tnpa5081 rebuild

Having my first try at a TNPA5081AF board

These are the parts that I isolated as failed the first sweep:

D16451 RF101L4S 400V 1A SHORT
D16482 RFN25TM4SW SHORT
Q16452 GT45G128 SHORT
Q16402 DG3D5020CSLW SHORT
Q16403 DG3D5020CSLW SHORT
Q16421 DG3D4020CSRP SHORT
Q16422 DG3D4020CSRP SHORT
Q16551 CPH5524-TL-E SHORT
Q16661 RJP63F3A SHORT
Q16660 R5007ANX SHORT
I wasn't sure about IC16521 (M81737FP), so swapped it given Q551 and D451 had failed.

I tested all the parts usually associated with IC773 and they all looked good as far as I could test (including 773!)



so I plugged the board in. got the green LED illuminating but then went 7 blinks and it looks like Ive re-killed some stuff:

Q16661 B1JAER000010 TRANSISTOR 1 RJP63F3A dead short
D641 - dead short
D642 - seems ok diode and resistance - will probably swap anyway
(Q621 622 seem ok but I think ill swap them now just to be safe, they seemed ok out of circuit before I tested the repair, but now that D461 is shorted I think ill play it safe this time round and swap them anyway)

a few other oddities i will likely just replace:

Q16402, Q16403 DG3D5020CSLW TRANSISTOR 1 DG3D5020 - these were showing dead short in circuit, but out of circuit they test OK (~2Meg resistance one way , turn on/off with turn on test)

the dead short resistance still shows up (probably the associated diodes), but I noticed its only with the polarity one way?? If I reverse the probes I get high resistance <Mohm - think ill have to look into this one a bit further!


here were a few things that I wasnt totally sure about the first time:
PC16461 B3PBE0000054 IC 1 PS9856-2-F3-AX
It wasn't measuring shorted across 5-8 but did show ~20kohm when measured in reverse polarity (red probe on the gnd pin and black on vcc) this was causing IC771 to measure ~4kohm when measured back the other way.
was this correct? I have a number of other failed boards I bought hoping to scavenge enough parts off them, it looks like almost all of the PC461 seem to measure 20-30kohm when resistance is measured in reverse across VCC-GND but found one on another board that wasn't doing this so swapped it. perhaps I swapped in a bad one thinking the others were bad?


I was extremely careful to test the parts associated with IC773: Q701, 702, D702 q818, all appeared unfailed and functional (transistors measure appropriately for their type using diode test B-c B-e etc) I took Q701 and 702 out and measured them out of circuit and they showed good. IC773 likewise did not show any low resistances or any unexpected measurements when compared to what would be expected off schematics

Obviously with Q661 dead I suspect I missed something in the inverter circuit but having pulled out Q701 Q702 D702, Q818, R707 they all test good out of circuit, so i doubt it was one of those. The only thing I could think of was it possible the IC773 to fail open circuit, it looks like reading this thread that it seems to ALWAYS fail and always be shorted or low ohms?


any guidance would be much appreciated!

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Msg is for tw2005
I decided to take a look at the tnpa5105 board again with the 6 blinks and found that Zener Diodes 871 and 872 blown. replaced them and now I don't have any blink code and I do have a picture the problem is that the picture is noisy and low in brightness both when I display the menu and picture from HDMI, do you have any idea as to what should be the problem now?
Can you help me with that

I would post an image of the issue.

[will_santana]

Re: Panasonic sc tnpa5081 rebuild

Msg is for tw2005
I decided to take a look at the tnpa5105 board again with the 6 blinks and found that Zener Diodes 871 and 872 blown. replaced them and now I don't have any blink code and I do have a picture the problem is that the picture is noisy and low in brightness both when I display the menu and picture from HDMI, do you have any idea as to what should be the problem now?
Can you help me with that

I'm not a specialist but the service manuals say something about adjusting the SC board presets in the service menu. Maybe that's the question.

[11alon11@gmail.com]

Re: Panasonic sc tnpa5081 rebuild

Msg is for tw2005
I decided to take a look at the tnpa5105 board again with the 6 blinks and found that Zener Diodes 871 and 872 blown. replaced them and now I don't have any blink code and I do have a picture the problem is that the picture is noisy and low in brightness both when I display the menu and picture from HDMI, do you have any idea as to what should be the problem now?
Can you help me with that

[will_santana]

Re: Panasonic sc tnpa5081 rebuild

Tks, TW2005

I'll keep an eye open on Q661.
I'll go silent 'till the board arrives but I've subscribed to the topic. Hope to see you guys in about 60 days.

Bye

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Thank you so much, TW2005.
It makes me more confortable with teh SU and SD boards.

I'm sure some kid or really bad "pro" had some praticing time on my boards.

I'll try the SC50 test (did it with the original one before removing it).

Let's hope the board is really brand new and I don't get taxated on the board's arrival (we have a "little" 60% import tax down here that combined with some others can more than double the cost). And if the board fails or burns in the process, the cost of acquiring another will make fixing the TV cost ineffective.
I'll try a visual spection and testing the diodes. Any other thing I can test?
How to test the mosfets and IGBTs?

Att

Q661 is probably the first part I'd test for short, always bad when this board goes 99.9% of the time

[will_santana]

Re: Panasonic sc tnpa5081 rebuild

By that sounds like the sd su are ok.

interested though in all those other issues. No way that's from factory, someone has been busy with a soldering iron in there.

When you get the new SC, you can do the 7 blink isolation test. That's where you connect the SC as normal, jumper the 2 pins at sc50, do not connect the sd or su , do not fit the 4 Vfg bolts that bolt the sd su. Turn the TV on and if it tirns on, no shutdown or error blinks, nothing goes bang then the SC should be ok. then hook up the sd/su as normal,

Thank you so much, TW2005.
It makes me more confortable with teh SU and SD boards.

I'm sure some kid or really bad "pro" had some praticing time on my boards.

I'll try the SC50 test (did it with the original one before removing it).

Let's hope the board is really brand new and I don't get taxated on the board's arrival (we have a "little" 60% import tax down here that combined with some others can more than double the cost). And if the board fails or burns in the process, the cost of acquiring another will make fixing the TV cost ineffective.
I'll try a visual spection and testing the diodes. Any other thing I can test?
How to test the mosfets and IGBTs?

Att

[tw2005]

Re: Panasonic sc tnpa5081 rebuild

Hi, guys. New here. Posting from Brazil, so forgive my english.

Let me summarise the best I can my drama:

I have a Pana P50V20B for about 5 years. Best TV and image I ever had. Some random day, when leaving the house, turned it off with the remote and bang! The 4 blinks of dead.
Took the set to the Pana's service. The first one gave me a estimative around US$ 320,00 to change the power source (P board). If that wasn't the problem, they would charge more to the new componet. Took straight to another service. After two days thay called and said the TV was beyond repair.
Took the set home and what a surprise when now the set don't even blink. Completely dead.

I've found the service manual on the internet and decided to fix it my self with my intermediate electronics knowledge.

Following the service manual found some fuses and other stuff dead on the P board. This was the state I've found the P board:





Various dead, poorly or completely unsoldered components. My bad I took it straight from one service to another so I cannot pinpoint wich one did it.

As I wasn't not confortable messing with the PS (one mistake could burn the rest), decided to order a used working one for about US$ 60,00.

Beside this "burnt" resistor I plan to swap with the original board (one single item I'm fine with), the TV got back to the 4 blinks (first thought of a real PSU fault but not. I'll get there later):



After reading A LOT of foruns, this whole topic and others here, I've isolated the problem at the SC board. After removing it, no surprises. Again, dead components and poor or no soldering:





Even my assistant agreed they did a sh*tty job:



Beyond the visibly messed components I've found other dead short diodes and so on.
Again, I'm not confortable messing with this kind of detail. So I've ordered a supposedly brand new board from china (US$ 115,00). It will take about two months to arrive, but got a few questions:

1 - I've checked the SU and SD boards according to this (and other similar) video: https://www.youtube.com/watch?v=-JVLWpcIxJQ
I've found no shorts on both boards. Using the meter in diode mode, it's an open circuit in one direction and about 750 ohms in another. As they can blow the new SC board, is there anything else I gotta check before connecting it all back?

2 - What kind of tests can I do on the new SC board when it finally arrives so I can assure it's fine before starting the TV?

That's all. Forgive if it's a long post, but a long history too (lot other things i've suppressed).

Thanks in advance

By that sounds like the sd su are ok.

interested though in all those other issues. No way that's from factory, someone has been busy with a soldering iron in there.

When you get the new SC, you can do the 7 blink isolation test. That's where you connect the SC as normal, jumper the 2 pins at sc50, do not connect the sd or su , do not fit the 4 Vfg bolts that bolt the sd su. Turn the TV on and if it tirns on, no shutdown or error blinks, nothing goes bang then the SC should be ok. then hook up the sd/su as normal,

[will_santana]

Re: Panasonic sc tnpa5081 rebuild

Hi, guys. New here. Posting from Brazil, so forgive my english.

Let me summarise the best I can my drama:

I have a Pana P50V20B for about 5 years. Best TV and image I ever had. Some random day, when leaving the house, turned it off with the remote and bang! The 4 blinks of dead.
Took the set to the Pana's service. The first one gave me a estimative around US$ 320,00 to change the power source (P board). If that wasn't the problem, they would charge more to the new componet. Took straight to another service. After two days thay called and said the TV was beyond repair.
Took the set home and what a surprise when now the set don't even blink. Completely dead.

I've found the service manual on the internet and decided to fix it my self with my intermediate electronics knowledge.

Following the service manual found some fuses and other stuff dead on the P board. This was the state I've found the P board:





Various dead, poorly or completely unsoldered components. My bad I took it straight from one service to another so I cannot pinpoint wich one did it.

As I wasn't not confortable messing with the PS (one mistake could burn the rest), decided to order a used working one for about US$ 60,00.

Beside this "burnt" resistor I plan to swap with the original board (one single item I'm fine with), the TV got back to the 4 blinks (first thought of a real PSU fault but not. I'll get there later):



After reading A LOT of foruns, this whole topic and others here, I've isolated the problem at the SC board. After removing it, no surprises. Again, dead components and poor or no soldering:





Even my assistant agreed they did a sh*tty job:



Beyond the visibly messed components I've found other dead short diodes and so on.
Again, I'm not confortable messing with this kind of detail. So I've ordered a supposedly brand new board from china (US$ 115,00). It will take about two months to arrive, but got a few questions:

1 - I've checked the SU and SD boards according to this (and other similar) video: https://www.youtube.com/watch?v=-JVLWpcIxJQ
I've found no shorts on both boards. Using the meter in diode mode, it's an open circuit in one direction and about 750 ohms in another. As they can blow the new SC board, is there anything else I gotta check before connecting it all back?

2 - What kind of tests can I do on the new SC board when it finally arrives so I can assure it's fine before starting the TV?

That's all. Forgive if it's a long post, but a long history too (lot other things i've suppressed).

Thanks in advance

[11alon11@gmail.com]

Re: Panasonic sc tnpa5081 rebuild

I decided to take a look at the tnpa5105 board again with the 6 blinks and found that Zener Diodes 871 and 872 blown. replaced them and now I don't have any blink code and I do have a picture the problem is that the picture is noisy and low in brightness both when I display the menu and picture from HDMI, do you have any idea as to what should be the problem now?

[peteburns]

Re: Panasonic sc tnpa5081 rebuild

So, the 50" plasma TV works fine again, this time I was lucky, only the SC board was faulty. Just to mention those "100% repair kits" - don't rely on them at all, at least in my case they wouldn't contain all the failed components, meaning the whole board would fail again...

[peteburns]

Re: Panasonic sc tnpa5081 rebuild

Thanks for that link, but it explains sustain board working principle in details. In this topic it is more important to describe scan board instead, and, even more importantly - from practical point of view, not theoretical...People don't actually need to know, how exactly the board works, but they need to know, how to examine components, find faulty ones and measure all the important spots in order to make sure all the power devices receive correct signals, so they don't experience big bang while switching on :-) Even the advice of using some resistor or light bulb at VSUS to protect the components is not correct, it will not protect enough and that's not the way any board should be tested...As mentioned many times before, any small overlooked component can cause some signal missing or distorted with the obvious result of immediate bang, or as in tw2005's case after 90min or so - both are not good enough and can be avoided :-)