Panasonic th-p50v20a - 4 blinks (sos4)

[tw2005]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

ok, try g-e for the "cge" parts (they are igbts.)

q661=.000
q452=.000
q421=.000
q402=.000
q403=.000

[tom66]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

OK, try G-E for the "CGE" parts (they are IGBTs.)

[tw2005]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

q660 red on g/s, blk on D = .000, REVERSE =.000

Q661 IS MARKED C,G,E

Q452 IS MARKED C,G,E
Q402,Q403 IS MARKED C,G,E
Q421 IS MARKED C,G,E
D482 A,K,A

[tom66]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

Try touching one probe on gate/source and the other on drain, this will ensure the FET is not being turned on by stray noise.

[tw2005]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

All pins are shorted no matter which way including reversing the polarity on a Fluke 73 in diode mode.

I'm talking .000. You can take my word on it. I would not believe it myself reading it but no bull. Quite incredibly strange!

Ok, maybe small lie. I can get 0.01 and 0.006 but same result both polarities and more than one direction still bad IMHO. Most are .000 though.

[tw2005]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

It seems very unlikely to me. How are you testing them? From source to drain, is it reading zero or almost zero?

All pins are shorted no matter which way including reversing the polarity on a Fluke 73 in diode mode.

I'm talking .000. You can take my word on it. I would not believe it myself reading it but no bull. Quite incredibly strange!

[tom66]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

It seems very unlikely to me. How are you testing them? From source to drain, is it reading zero or almost zero?

[tw2005]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

I would say it's unlikely they are all bad. You will have to remove them to test them out of circuit. Are you sure the buffers are OK, too?

Well guess what. I did and they are dead short. hard to believe that many in different spots.

I tested gnd to the output of the buffers-no shorts. Then tested the inputs at the buffers from the sc board, no shorts either.

Any tricks you know for testing the buffers? It's not an area I'm overly confident with.

If this was a samsung ysus I'd have better luck finding components I reckon.

[tom66]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

I would say it's unlikely they are all bad. You will have to remove them to test them out of circuit. Are you sure the buffers are OK, too?

[tw2005]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

Sorry about the res. 7 dead shorts.

No jokes about my trendy slippers

[tw2005]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

Can you show a picture of where the FETs show as shorted? I had a similar issue, but it was just one FET that was shorted, I was able to replace that and it worked.

Do you mean on the board, or what heat sinks they are on?
Just give me some time to work it out. There's 6 heatsinks with 9 parts off 7 of which were dead short .

[tom66]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

Can you show a picture of where the FETs show as shorted? I had a similar issue, but it was just one FET that was shorted, I was able to replace that and it worked.

[tw2005]

Re: Panasonic th-p50v20a - 4 blinks (sos4)

Here's another question. Has anyone used different revisions of Sc boards to what was originally installed in their Panasonics?

I see the SC board is used on 42",46" & 50" models. having a quick look at the components there are some differences like CAPs between them but the 50" at a glance look the same.

[tw2005]

I have a 4 blink code on P50V20A full HD about 14 months old.

Interesting fault to say the least. I isolated the SC board and the blinks changed, green led lit on the SS and managed to measure VS at 204 volts under this condition for the 3 seconds the set powered up.

When the Sc is connected 4 blinks and no led lit on that board or the SS and the set turns off straight away.

So I've headed for the SC and so far there are banks of FETs and diodes dead short all over this board.

No wonder the PSU is spitting out 4 blinks with dead shorts. The VS does not even get a raise when the SC is connected.

I checked the buffers, nothing burnt and did not find any shorts.

Here's the list and I am using the TC-P50VT20 GPF13DU Chassis service manual to fault find this as I can not find my exact model.

TH-P50V20A

SC-board TNPA5081

Board Loc# Schematic# Part# description

D482 D16482 B0FACP000003 DIODE (RFN25)
Q452 Q16452 B1JAEP000012 TRANSISTOR (45G128)
Q402 Q16402 DG3D5020CSLW TRANSISTOR (DG502LW)
Q403 Q16403 DG3D5020CSLW TRANSISTOR (DG502LW)

Q421 Q16421 DG3D4020CSRP TRANSISTOR (DG402RP)
Q660 Q16660 B1CERR000042 FET (R5007)
Q661 Q16661 B1JAER000010 TRANSISTOR (RJP63F4A)

Can any brainiacs out there help with datasheets or substitute parts? Searching is not getting me far. It's as if Panasonic use custom parts or numbers.

Very frustrating.