Panasonic Viera TH-P42S10A SOS 5 Blinks

[tw2005]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

I'm 4000k from home so not much I can check out and I only have the TNPA5081 boards to maybe see what the optos do when probed although they won't be the same part?

IGBTs do make a pop without blowing apart. That's what I found.

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

After removing the blown q401,402,421,422,661 and d865 - many of the other things that tested bad in circuit are ok after all. Notably, 402 blew this time and 401 did not. Last time it was the other way around.
Will post details of found problems later but looks like mostly just the same ones have gone again.

Thinking I must have missed something on the SC, something that allowed it to run for 90 mins before carking it again..
Also still haven't found anything with holes blown in it etc that would explain the loud pop when it happened, which kinda worries me.

Looking at the fet drive circuit as a possible and also have seen the kits that have many of these parts in them- and have found most of it looking ok with a multimeter but this bit stands out:

PC461, the dual opto-isolator right before the 2 inverters on the fet driver circuit - is reading both directions between leads 3-4 on diode test which does not seem right.
Pins 1-2 read only in the forward direction so it's double odd that 3-4 would be any different, although the inputs are hooked up slightly different on the 2 looking at the schematic I still can't see why 3-4 should do this.

In the THP-42S10A schematic(sorry thought i already included this earlier - attached at bottom of this post) - page 72, you can see the fet driver circuit and PC16461 with its internal led's on pins 1-2 and 3-4 with pin layouts 1An-2Ka and 3Ka-4An.

Diode check between leads(pos,neg):
1-2 1.51
2-1 oL

4-3 1.51
3-4 1.02

<Questions>
Does this seem normal or not given the way things are wired?
Is this fet driver circuit likely area that could have an intermittent problem but still function for 90 mins?
Also a question for Tom and tw especially but all answers welcome - what would you be doing from here if this was on your benches?
Oh and just to confirm, if the little rise in voltage from removing c-boards is enough to suspect a panel or c-board even though it can still display a good image or would you look elsewhere now?
</Questions>

I'm starting to look more at this tnpa5081 rebuild thread for clues more than the original 7 blink thread I linked earlier, although that was super helpful getting me to here.
Will go over some other components mentioned here in next few hours too.

https://www.badcaps.net/forum/showth...2&pp=40&page=6

Thanks for taking time to read. It's difficult/impossible to be both detailed and short.

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Thanks I was curious if writing a 9 like a P was normal but i guess it would be if someone is doing them every few seconds as they leave the production floor.

It measured fine when i tested it for 209 with the SC still out last time but I didn't check after the repair went back in. Next time around I will verify the important voltages with the SC back in before trying to test with movies etc.

[tom66]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Those numbers are written on by hand by the technician in the factory which checks each panel. 42" & 46" FHD panels are notoriously difficult to manufacture and the tolerances are naturally poorer, so they are hand calibrated.

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Did what i should have done earlier and disconnected the c-boards and checked the p5v with and without the c-boards as Tom suggested:
(SC completely removed from the unit and all other connections in place)

With both c-boards attached - 4.982v
Without c-boards attached - 4.995
C1 or C2 connected 1 at a time with the other disconnected - 4.986

So there was some rise. To me, that seems within reason though. Maybe it will mean more to one of you experienced folks.

Embarrassingly it was only 3 screws to loosen the main board cradle and be able to get at the c-board - SS board connection.
Sorry for not taking the time to do it earlier Tom, really am embarrassed. I think it's you I've watched a lot on youtube just to learn from even if it doesn't relate to my tvs(from vids back with the old cro scope up to the Rigol dso) so don't think I wasn't listening - just stupidly concluded that even if there was a problem I wouldn't be able to do much about it and didn't notice the main board was just in a cradle that could be moved aside.. and thought i had to undo all the screws and wiring and then redo them etc.

Starting to turn into a blog here. Feedback is needed to avoid this and would be most appreciated - even if it's just to say hi!

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

A question about VSUS because this sticker has bothered me from the start:
In the picture below you can see the panel label for this tv with the VSUS written in some dodgy hard to read way. I assume, and the person who last set the VSUS did too, that the VSUS is 209v.

So my questions is, if this is really a hard to read 201(with a D on top for whatever reason) and not a 209 - would setting it to 209 be obvious when looking at the screen? - because the image looked great, not washed out etc.

And would/could this slightly high VSUS setting cause the SC to work excessively hard and possibly be involved in the problems I'm seeing?

Also I realized in my travels this panel model - MC106F16T12 is used in a few others and seems to be a common link on the various 42 models with similar SC failures, so for those who keep score that could be something to keep an eye out for. I would assume they all use the tnpa4829 variations for SC whenever this panel is used too so it could just be the SC's alone that fail but it could also be possible these panels are contributing to the SC deaths somehow.

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

- The usual suspects:
Q401 - shorted all directions
Q402 - shorted all directions
Q421 - shorted all directions
Q422 - shorted all directions
Q661 - shorted all directions
D865 - shorted both directions

New additions to this seasons 5 blink line-up:
D401 - shorted all directions
D402 - shorted all directions
D461 and D462 - 0.3v drop in normal direction, 1v drop in reverse
D621 and D622 - both showing 0.35v drop which i think is normal for them, but now getting it both directions A-K + K-A
Q621 and Q622 - showing shorted drain-source, but will do that if d865 is bad, so need to be re-tested later
Q660 - shorted drain-source, 0.14v drop on diode test in both directions on all others

^ so that is most of the foil side of board testing bad in circuit. Looking grim.

On the component side:
D673 and D674 both showing shorted, but will do that if Q661 is bad so need to be re-tested later
D624 - ok
D652 - 0.5v drop normal direction. 1.8v drop with leads reversed
D679 - 0.5v drop normal direction. 2.2v drop with leads reversed

And still checking..

I blame Will Ferrel. He was on the screen at the time doing his usual bad joke thing when the tv went bang and took it's own life rather than living with another 60 minutes of him. Which is a shame because I don't mind him and was enjoying it.

Got my C64 brain on today so things are going to take some time to process but in any case it looks like there is more damage in season 2 than there was originally.

Would prefer to find whatever little bugger components causing this but in the back of my mind there is a couple of SC boards on ebay for $120> that are starting to look like an option. Although even if i did replace the whole board at this point, can't be sure it won't just last another 90 minutes before the same thing happens again.

For now that's all i have. Will have a look at the schematic and see if i can make any sense of things but the way it worked for 90 mins has left me guessing.

All feedback is welcome down the bottom, if you liked this video please remember to like and subscribe blah blah

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Correction - after removing power and then plugging it back in it is showing 5 blinks again. Hello square 1 - my old friend.

The fuses on the p board all tested ok so sadly that was not the pop i heard, then i plugged it back in to test for 3v at pin9 of P7 like the 4blinks troubleshooting suggests when i noticed the 5th blink - and looked over at the previously repaired components.

I can see q402(2pg011) looks burnt so good chance it's gone, and possibly the pop i heard. Interestingly, the original 402 tested ok after removal but i replaced it with a new one anyway since it was already out.
D865 is also showing shorted again which can also mean q621 or 622 is shorted drain-source, but last time after d865 was removed the short was removed with it and they seemed ok.
So the million dollar question now is really, why did the SC cark it again so soon but also worked fine for about 90 mins?
Is it possible that tired caps on the SC itself could cause the other parts to overwork themselves to destruction just to maintain operating voltages?

I don't have an esr meter or anything other than the capacitance test on the multimeter handy sadly so there seems little point in removing them and it's just a theory, but since it ran for 90 minutes whatever the extra problem is seems to take it's time warming up before stressing the fet drive circuit beyond what it can take. Just guesses there, the fact it took x minutes could just be random or related to something on the screen at the time etc. etc.

I'll pull it out again, test the same areas and get back with results but pretty well expecting to be back to square 1 all round since d865 is definitely shorted both directions.
Have here 1 more set of spares for q401, 402, 421, 422, 661 and d865 so will have to make them count and work out what else is wrong before trying again.

I took a couple of months getting to this stage, taking my time. Spose another couple won't hurt but dangit! All looked so nice too, great picture.
The only thing about its operation that stood out as even remotely odd was the volume had to be cranked to 60ish to be at a decent movie level volume and I had some pc 2.1 self powered speakers hooked up via the headphone jack and headphone volume set to 100. But, don't know if it's because of my source video(an mp4 playing via pc hdmi) or if 60ish volume is pretty normal for these tvs. Should hardly blow an SC in any case i would think..

Anyway I'll go get the SC out and see what's new and go from there. The 4 blinks i guess is just triggered initially when it fails and you don't get the real sos until it has a chance to self check after getting plugged in again or something like that. Fairly sure the 5 blinks will be correct.

When i said i would get back on track earlier, really didn't mean all the way back to 5 blinks.. jinxes are out to get me i tell ya!

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Ok, something is seriously wrong today and i have a bad case of the moz going on and everything i do or say is somehow jinxed..

I was just testing it and all good for about 90 mins, then a good loud pop, and now 4 blink sos. Died within about 30 mins of my last post.

Far out.. I know from my reading along the way this means power supply so will start there.

I'm wondering if you were right about the panel or c boards tom. I never did disconnect the c boards to see if the 5v changed, mostly because i was lazy and there was just too much to disconnect and re-connect to get at them on this model since the main board covers the lower part of the SS etc.. so maybe that is what bit me here. But the panel did all look great when it was working.
Hopefully not the panel, and just an anomaly from being fiddled with and really is just the P board but seems suspect that if i fix the p board it might just happen again.
I guess i might remove all the bits in the way and test the p5v without the c boards attached like i should have done earlier if i can get the P board going again.

Anyway, here we go again, weeeeee.
4 blinks time. Any and all suggestions welcome!

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

First things first:






So, I was going about undoing all the screws and removing the buffers and right as I was about to fold them aside, I noticed the small ribbon between the SU and SD was not connected(oops doi, apparently i forgot it earlier). So, knowing what this could mean i put all the screws back in again.. and reseated the ribbon hoping this was the cause of the 7 blinks before disconnecting the buffers- and bamf, panel fired up first try.

Wuhu!

Stoked!

For the logbooks, i have some theories and other stuff later but for now at least it shows 5 blinks can happen with the same failed SC components as the more common 7 blinks.

Will post back later with some bits and pieces to finish up, but for now it's job done and time to test it by watching it. So I am going to go and celebrate the proper way - watching motorsport and boobs simultaneously in 1080p while drinking whiskey.

Thankyou thankyou!

(image taken on phone, sorry about the quality but the logo is still visible to get the idea across)

[tw2005]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Yeah, found it but left it now that MW is out, set it to lowest res so not too bad on the download.

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Sorry link I'm using is:
http://www.dailymotion.com/hub/x8p7?...#video=x10uqt7
I guess you got sorted as you can while mobile anyway but just incase. If that doesn't work i just found it from oogling lemans 24 hour live, big sponsored ad comes up.
All just changed a bit with no more webber.
That's the 2nd leader to retire from mechanical failure in the last 6 hours of the race, they were sortof only leading after the other guys failed earlier. Interesting race. Still plenty of time for more too.
But for now i'm off and when back I'll get the tv out and get back on track

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

lol yea. sorry mark!
unbelievable the power of the jinx!

[tw2005]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Ahh, I think we jynxed him. Stopped dead it seems.

limping back

[tw2005]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Thanks mate, planning to get into it again within a couple of hours and that's the top of the list atm.

Totally unrelated - for any car enthusiasts out there:

Le-Mans 24 hour race for 2014 has just over 2 hours left at the time of this post, streaming live via dailymotion.
Go Webber, Aussie Aussie Aussie!

bugger, don't have the bandwidth, away on a prepaid mobile broadband. Is he leading?

got a link?

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Thanks mate, planning to get into it again within a couple of hours and that's the top of the list atm.

Totally unrelated - for any car enthusiasts out there:

Le-Mans 24 hour race for 2014 has just over 2 hours left at the time of this post, streaming live via dailymotion.
Go Webber, Aussie Aussie Aussie!

[tw2005]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

I think all you can do at this stage is isolate the buffers, and do the SC50 jumper and confirm whether the SC is producing SOS7.

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Quick update: (more details later)
I replaced the components on the SC and re-installed it.
The transformer hissing is gone even with the SC plugged in, the SC board led is now working, nothing went pop or released magic smoke so those things are good - but the panel still didn't fire up. And i didn't have time to tinker any further or probe voltages.

Now it is giving 7 blinks instead but the SC led is at least working.

So, i plan try and isolate the buffers by disconnecting and unscrewing them from vf_gnd and folding them aside and then using the jumper on SC50 to bypass them and see if the panel fires up.
I was reluctant to try this test until now but i think this is the right time for it and it should tell me if the repairs to the sc have that board working.
- and i guess hopefully from there if the panel did fire up it would mean the su or sd are causing the 7 blinks and i'm not completely back to square 1.
Also plan to re-probe the replaced parts and vscn and 15v etc, but with the led now working on the sc board it seems the repairs have survived powering on at least, so i guess it would be wise at this point to eliminate the buffers before going back to the SC and tinkering any further. If i did, poking around the vscn and vad etc voltages on the SC and the fet drivers and their nearby circuitry and voltage regulator would be on the todo list now that i have power on the SC board for the first time. Anyway, that's down the track if the jumper test doesn't help first, and first things first.

So it wasn't a complete success and the easy win i was hoping for- but it also didn't end in anything going pop or releasing its magic smoke so i guess it's a positive progress as far as not being a panel shorting 5v but stil leaves more to solve.

I have time later today and 1 set of spares for the already replaced bits just in case they're useful, so would really love some feedback before getting into it again.

Schematic attached at bottom, page 72(actual page#, not the printed page#) has SC schematic and page 37 has block diagram of 7 blink sos.

and a link to a troubleshooting guide for 2009 plasmas:
http://www.scribd.com/doc/114317415/...echnical-Guide

[DoubleDratt88]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Thanks guys I have much respect for your opinions on the topic, have seen you both in many other forums so thanks for taking the time to read and post back.
I'm just processing your comments tom. Unfortunately my brain is running about the same as a c64 right now. (not the fancy new slimline ones with lightning fast 1541 II floppy drives and epic fast-load cartridges either)

I am curious myself why this one is showing sos5 and not sos7 like the others in the linked thread. Since I already have the SC out and a little dismembered in surgery I'm not sure exactly what you meant about disconnecting the c boards though.
Did you mean even with the SC not connected and p5v showing 4.95 that i might see a rise if the c boards or panel have issues?
I can see how doing that back when the SC was still in place and bringing down the p5v to 4.6v that it could rise. I guess what i don't see is how it can rise much from the 4.95 now that the SC is removed.
Never the less, i will take your advice and try to be sure the panel and c boards are ok before going too much further.

In this tvs case i actually have some history too. It was very well cared for, no signs of impact to screen or body etc. Previous owners contacted panasonic and were quoted something like +$2-300 for a new board +hourly labor charges +service fee which pretty much added up to new tv, so that's what they did instead. So I really haven't had much reason to suspect the panel, but I'm also not sure how they quoted that. Not sure if a tech actually looked at it or if it was over the phone etc, I don't know. Will still look into the panel and c boards though - being a bit more sure everything is ok before wasting time and parts is why i posted in the first place.

We had a hot streak in summer this year that would have surely brought many appliances and vehicles and anything else already on it's last legs, to its knees. This model from what i have read is the first 42" they did with no cooling fans too. Maybe they should have kept the fans.. Just a theory or maybe coincidences but i got it just a few weeks after that hot spell too.

I'm actually glad in an odd way that you didn't have much to add tw. I know you're also very knowledgeable on these pannys so in a strange way it's made me feel more confident that I'm already on the right track i guess I'll keep a seat warm in the front row for you just in case you think of anything to add later.

Will post back when i have anything worth adding. Planning to get the tv out again later and try and re-test some more with a fluke and compare that to my cheapo readings taken earlier and also run through whatever i can find on checking c boards and panel, before taking the plunge and installing the components and SC again.

[tom66]

Re: Panasonic Viera TH-P42S10A SOS 5 Blinks

Note that on a lot of Pannys the panel address fire-up is the last stage. An SOS7 etc. can hide a panel short SOS5 as there's usually a MOSFET somewhere for switching the 5V (or the ICs get an enable line) then the Vda (~70V) goes high.