Panasonic tc-p50s30 su,sc,ss repair help

[bman4]

I have a TXNSU1MNUX Panasonic SU (TNPA5336AM) that has a sigle top buffer ic shorted,
you can actually see a tiny hole on it, this failed buffer ic resulted in failure of sc and ss.

Do i need to just replace the buffer ic or is there other smd's that need replacing?

The sc is shorted from sc2 upper pin 3 to ground screw.
The shorted fet/diodes on sc
2x:rfn20 ns3sw
3x:rf1501 ns3s
1x:rfn10 ns3s

The ss has a shorted center pin to ground.
The shorted fet/diodes on ss
2x:rf1502 ns3s
The ss also has the top brown cap 220v 120uf with residue on top unlike the sc,
any recommendation on replacement?
Im just gonna order it now and replace it while i can i cant afford a tester yet.

Is there any other smd's that i gotta replace such as the repair kit you can buy?
For me to order the repair kit is a waste of money because they are not all faulty.
I just need to confirm before i order so evrything comes in at the same time.
I want to thank you all for the opurtunity to joint the community to learn.

sincerely,
bman4

[tw2005]

Re: Panasonic tc-p50s30 su,sc,ss repair help

I have a TXNSU1MNUX Panasonic SU (TNPA5336AM) that has a sigle top buffer ic shorted,
you can actually see a tiny hole on it, this failed buffer ic resulted in failure of sc and ss.

Do i need to just replace the buffer ic or is there other smd's that need replacing?

The sc is shorted from sc2 upper pin 3 to ground screw.
The shorted fet/diodes on sc
2x:rfn20 ns3sw
3x:rf1501 ns3s
1x:rfn10 ns3s

The ss has a shorted center pin to ground.
The shorted fet/diodes on ss
2x:rf1502 ns3s
The ss also has the top brown cap 220v 120uf with residue on top unlike the sc,
any recommendation on replacement?
Im just gonna order it now and replace it while i can i cant afford a tester yet.

Is there any other smd's that i gotta replace such as the repair kit you can buy?
For me to order the repair kit is a waste of money because they are not all faulty.
I just need to confirm before i order so evrything comes in at the same time.
I want to thank you all for the opurtunity to joint the community to learn.

sincerely,
bman4

kinda strange you find all the SMD diodes shorted on both the SC and SS but no IGBTs? You sure you know what you're doing? Ever removed and replaced a panasonic buffer IC before? I know I have not but getting them off without damaging the tracks is almost impossible.

By the way pin 3 SC2 is gnd, ,so gnd-gnd = lead resistance of your meter
and , center pin(pin 3) on SS11 also is gnd so you know already what that should read.

I think, stop, take a breath , read a bit about some basics, get the manual, study the block diagrams and the schematics for the boards you refer to first.

'm also going to assume you check those diodes wrong, they are common cathode and dual anode meaning if you measure across the 2 legs they'll appear to be shorted, but the tab to either of those legs will be like a diode , if it's good.

So, good way for us to get back to fixing this broken TV.

step 1, tell us what happened symptoms, how many blinks - I'm guessing we have 7

step 2. forget about that suspect cap on the SS but feel free to upload pictures using advanced , manage attachments, no bigger than 2000x2000. Caps in these are high quality longlife, and this is a relatively young TV.

step 3. check across the 2 pins at SC2 the resistance. If it's over 300k ohms and into meg ohms then the SC could be ok, in which case

Step 4. Isolate the su/sd from the sc ie the 3 connectors , 2 on the sd, 1 on the su. now remove the bolts that gnd the sd/su to the sc, they will be inline with ose other white connectors, could be 4 of them or even 3 but make sure no gnd bolt is left attached . they refer to these as Vfg or floating gnd because it's gnd with respect to the cct on the SC not chassis gnd. That's why they attach to metal posts on the SC.

Right, step 5. the SD/Su buffer isolation, SC50 jumper test. this will prove if 7 blink is SC or not. With the above disconnected but everything else connected normally, on the SC board, a small white connector SC50, 2 puins they need to be shorted together. Now, turn the TV on, if all else is good and you found no short at SC2 then the TV will turn on, no error blinks. If it shutsdown with 7blinks then the SC will be also faulty.

I am assuming you do have a 7 blinker of course.

other notes, clean up all gnd pads on the sc , check the ss too, replace those mounting bolts with normal bolts with washer set. The ones Pansonic used here work loose, causing bad earth on the Sc and ss board and arc, maybe the cause of these failing and/or the buffer board damage.

Plenty sell these bolts on Ebay or Shopjimmy

If the Tv passed with that SC 50 test, then assuming you're right I would not try buffer ic repacement unless you are very experienced in do that type of work. find a good used, or repair using someone like ModuslinkPTS orEbay but Modus can be trusted from what I read. I know being in Canada is goingf to make that expensive i suspect for shipping etc.

If it's only SU, you may get away with using another 50" SU board say from a GT with heatsinks or the ST. Someone very recently used st30 su in a s30, try to doi a search on your tv model, bound o get plenty of hits as they commonly fail SC boards, buffers not as much. i did a similar model with shorted sc which needed 4 transistors, buffers survived, screws were loose and burn marks.

Also, better tell us how you have checked the sd and su boards to know if they're good or bad. If there's a hole in an IC that's obvious but usually no visual clues in a lot of cases requires ohming it out.

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

I though one was atleast a fet from a ebay ad, i just rechecked all dioes.
Ive been trying to find the sc 50 jumper, i dont think my sc board has one.

The reason i though the ss was dead because i pulled the ribbion cable jumpers and i was able to get it to stay on with no picture or blink code.
i tried some more test when trying to find sc50 so i just pulled the ribbion cables again, this time it wouldent come on without the ss ribbion cable disconnected and gave me a 8 blink code from orginal 7 indacting ss.

Im new with a meter,i have just been just checking the 2 legs!

Ive been practicing with a old computer mother board, i was susccessful at removing and re placing smilar smaller ic such as audio ic so im prety confidant,if anything ill buy a new one.

Im not going to remove the buffer ic with just a soldering iron but with a reflow gun and preheater.

It's been awhile,i gotta pull the tv from storage,ill get back to you with updated test's.


sincerely,
bman4

[tw2005]

Re: Panasonic tc-p50s30 su,sc,ss repair help

well I'll just warn you that panasonic use a thermal silicone sealant / adhesive and it's run under the IC and all through the legs. I managed to practice on some dead boards and after 2 fail attempts manage to work out a way. If you attack it straight up with heat you may be disappointed if any of that silicone hangs on especially the legs as those tracks lift real easy. there's a lot of pins there.

i found acetone helped breakup the silicon, wooden tooth picks to gently rub it away, then very carefully sliced the legs hard against the casing but careful enough not to slice through the board or some tracks may get cut.
. This allowed me to keep working the acetone into it and then gently twist the ic body off leaving the legs behind and then kept working the acetone in, then very carefully used an iron to desolder the legs. The acetone definitely changed the properties of the silicone and it ccrumbled easier but won't dissolve it.
Ricosavy has a post which I added some pics to and flocko has just got in on looking at ic replacement, he may be better atgiving tips but given how rare these boards are tofind and that they can be repaired the core is quite valuable at this point. otherwise one mistake and you're looking for a board , but hey, you know what you can do but if you have any other panasonic buffers to practice on first I would start there.

Now back to the boards. All those items you list are 100% fast rectifier diodes.

SC50 I'll find it for you if you hang around for a bit. I think you need to try that first.

I'm sure i'd be happy if i discovered i only needed 1 board as opposed to 3.

I think some manuals and guides would help you too understand the blink codes and what happens with what disconnected

[tw2005]

Re: Panasonic tc-p50s30 su,sc,ss repair help

right , you should be able to just locate in this pic.

the training guide not exact model but very closely related St30, page 88, check that out for the SC50 test, important those Vfg bolts are out, someone did report trying this with them in and fried the buffer boards.

There's also a 7 blink procedure, a guide on what blinks are expected with things removed, resistance checks for the sc,sd,su, etc,etc.

give the sc50 test a shot and if it passes, follow up with resistance checks on the Sd,su although sounds Su is shot with a hole.

and then you may be lucky enough and just focus on getting a SU sorted and should be back in business

Just check and double check you've reconnected anything you've previously touched. Lost count now the number of times a lead is missed and just throws a spanner in the works fault finding with an unknown variable.

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

I just tried with the su an sd boards competly out and now i get the 8 blink.

I tried again without the ribbion cable to the ss a sc and bottom jumper and my power supply sounds kinda weird and would not light up at all, im letting it sit for a bit to get cleared.

Wow the sc 50 is right in front of me i was looking for 2 bare pins.

Everything tested fine now that i tested right but the sc was a 190 ohms and riseing on the tester set to 200k.

Do i put a hardrive jumper in then plug it in or plug it in and put the jumper in?

[tw2005]

Re: Panasonic tc-p50s30 su,sc,ss repair help

I just tried with the su an sd boards competly out and now i get the 8 blink.

I tried again without the ribbion cable to the ss a sc and bottom jumper and my power supply sounds kinda weird and would not light up at all, im letting it sit for a bit to get cleared.

Wow the sc 50 is right in front of me i was looking for 2 bare pins.

Everything tested fine now that i tested right but the sc was a 190 ohms and riseing on the tester set to 200k.

Do i put a hardrive jumper in then plug it in or plug it in and put the jumper in?

read the guide first. but have tv off, set it up with evrything connected correctly but sd/su connectors removed, 4 vfg bolts removed, short sc50 , hdd jumper may fit, I have a small alligator clip I can get half the clip to sit across the sc50 pins and the other half outside the case and just having it clamped like that usually shorts those pins, then just power it up and se if it stays on. then shut down and investigate buffers. If it fails and still has 7 blinks Sc is also bad, anything else well we'll see but I'm nearly out for time nee to hit the sack.

also if sc20 is disconnected it triggers 8 blink, can't assume just because you have 8 blink SS is bad. read the trainer.

[tw2005]

Re: Panasonic tc-p50s30 su,sc,ss repair help

need to now if 190 in 200k means 190k or 190 ohms but that connection can read in megohms. I don't like $10 meters, hope you have something reasonable , definitely worth investing in a good autoranging meter like a fluke, even a basic one which is all i have.

[tw2005]

Re: Panasonic tc-p50s30 su,sc,ss repair help

Even if the SC bad, it's already dead so doing this will either prove good or bad any way. I'm hoping it's good and just a bad buffer.

if SC2 was dead short that can cause locked solid LED or 14 blinks too.

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

I have a pro teck d946,up to 1000v dc and 750ac.
I was going to use just the 200 ohm setting but it has an ajustable pot so i just figured 200k is the same, ill try again on the 200 setting.

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

Okay the tv came on with a green light but the sc made a weird buzzing noise,i did torque the screw pretty good, no smoke so that a plus.!

The buzzing is comeing from the upper portion of the sc, it seem's to be a upper dioed or transistor.

I re torqued the screw a couple time to clean them up but still buzzing

[tw2005]

Re: Panasonic tc-p50s30 su,sc,ss repair help

Okay the tv came on with a green light but the sc made a weird buzzing noise,i did torque the screw pretty good, no smoke so that a plus!.

yeah they can, could be loose or maybe because no load , either way the rest of the tV should be fine, just work out if just SU is bad or both sd/su but very recently there was a 50s30 bad Su , sc good.

I'd only check these with a meter, don't try running with just one board just in case something gets damaged, not worth the risk, hard enough to get parts these days with panasonic getting out of plasma Tv

I have to go, have a read , I find those trainers really interesting

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

Thank you for your help tw2005.
Have a wonderful day!

sincerely,
bman4

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

Do u think i should just replace all upper smd diodes and fets just for the hell of it.
Im thinking that the upper buffer failure caused this because it's only in the upper portion and maybee the component is on it way out.

I have a stethoscope and could try to narrow it down!

[tw2005]

Re: Panasonic tc-p50s30 su,sc,ss repair help

Do u think i should just replace all upper smd diodes and fets just for the hell of it.
Im thinking that the upper buffer failure caused this because it's only in the upper portion and maybee the component is on it way out.

I have a stethoscope and could try to narrow it down!

no not really. get the TV running first it may quieten down once it's all back and running

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

Understood!

Just got home,i fired it up and it did quiet down for a second,weird.

Im just going to order the screw's and the buffer ic.

I did read the whole buffer ic replacment thread and someone mentioned a silicone disolvent,ill look for one that's safe and effictive.

I look around for some more guides on how to remove the ic properly.

Now im getting a 8 blink error code without sc50 jumped when i orginally had 7 can't 100% confrim.

Dose this error refer to bad buffer, when i looked it up i came to a conclusion that it is failed ss, possibly because the ss goes to the panel just like the buffers.

[tom66]

Re: Panasonic tc-p50s30 su,sc,ss repair help

8 blinks is unusual, usually refers to SS board more than anything. Did you make sure to secure the link between SN/SC and SS boards?

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

Im pretty dam shure,im really good a ribbon cables.

This error occured after i only did the unplug sc ribbion and ribbion rigth below.

The set did fire with sold light then the next time it wouldent and i discovered 8 blink code witch led me to ss.

Then i just tried unplugign the ss ribbion cable and got solid light again.

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

The green light is on the ss tho i guess ill have to wait to see what happens.

[bman4]

Re: Panasonic tc-p50s30 su,sc,ss repair help

Can i mix a 50gt30 upper buffer with a 50s30 lower buffer?

Is there a list of substitutes buffers anywhere?