Panasonic tc-p50g25 10 Blinks

[andrewnelles]

Dug through some old threads on this, but didn't find anything identical to my situation. I've got a Panasonic tc-p50g25 that failed over the weekend.

It failed to power up and initially gave 4 blinks as the error, however it shortly after switched to 10 blinks, which is where it has remained. Unplugging/resetting had no effect. Neither did 12hrs of unplugged idle time.

I've removed the back panel and visually inspected all caps. No visual problems there.

Based on previous threads, I checked the following:

On the P-Board no shorts measured on TP5 or TP9, fairly high resistances picked up, creeping in value.

Pin 1 on P11 on the P-Board is measuring less than 1V when everything is hooked up. If I unhook P2 and P11, Pin 1 on P11 measures 200V on startup and slowly drops over time. Pin1 on P35 measures about 50V in the scenario, but drops over time.



Curious on what would be recommended to further isolate the source of the issue here.

Any help is welcomed. Thanks!


------Update-----

It's back to blinking 4 times again.

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

Dug through some old threads on this, but didn't find anything identical to my situation. I've got a Panasonic tc-p50g25 that failed over the weekend.

It failed to power up and initially gave 4 blinks as the error, however it shortly after switched to 10 blinks, which is where it has remained. Unplugging/resetting had no effect. Neither did 12hrs of unplugged idle time.

I've removed the back panel and visually inspected all caps. No visual problems there.

Based on previous threads, I checked the following:

On the P-Board no shorts measured on TP5 or TP9, fairly high resistances picked up, creeping in value.

Pin 1 on P11 on the P-Board is measuring less than 1V when everything is hooked up. If I unhook P2 and P11, Pin 1 on P11 measures 200V on startup and slowly drops over time. Pin1 on P35 measures about 50V in the scenario, but drops over time.



Curious on what would be recommended to further isolate the source of the issue here.

Any help is welcomed. Thanks!


------Update-----

It's back to blinking 4 times again.

Blown SC board, you'll find SC2 is shorted. Common failure on these.

search TNPA5081 and you'll find my lengthy thread.

TNPA5081AF (TXNSC1LPUU )

Near the end of the thread there should be a fault finding guide.

must resistance check SD/SU boards as outlined in that PDF before you fit a replacement Sc board.

Scarce and expensive to find now so you may have to do a repair/return with these guys unless you are brave enought to try repairing yourself.

http://www.moduslinkptstvboards.com/TXNSC1LPUU/

they have a sale on if you get it in before end of march.

March Hoops Sale!

All parts including Repair and Return are 25% off for the remainder of March. Use coupon code MARCHSALE at checkout!

http://www.moduslinkptstvboards.com/

Revisons AF, AP, AW will all work ok in the TV

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

I found these in the UK

http://www.lcd-plasma-parts.co.uk/in...earch=tnpa5081

Word of warning. I have a bad one of these from here but to his credit I got a full refund.
I've referred this place to someone else fo a G10 series and he was very happy with no issues.

Not always tested like they say.

By the time freight is added, probably close to a repaired board price and these will be used.

there is a subtle difference with the AW with a small ceramic cap added to the cct. If removed will be the same as AF,AP but I used one in my brother in laws Tv as is and been running 15months with nil issues and he's happy.

[andrewnelles]

Re: Panasonic tc-p50g25 10 Blinks

Alright, SC2 is measuring 0hms to the chassis. With the cable disconnected, Pin 3 on P2, the corresponding link on the PBoard, is also measuring 0 ohms.

If I power up with only the SC board disconnected, I get 7 blinks. If I power up with everything connected, it's currently giving 10 blinks.

Does this 100% confirm that the SC board is faulty? Is there anything I can test presently to confirm the the rest of the boards are healthy? Especially the P-Board?

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

7 blinks is correct for SC2 disconnected. You have the wrong pin. Pin 1 is Vsus, 3 is gnd so will show short gnd-gnd.

Just measure across the 2 pins at Sc2 - expect short.

likewise across p2 but should not be short but set to dc volts first and check there is not 200V residual still present at the PSU before you go measuring resistance or you will damage meter.

If you really want to confirm PSU, try disconnecting the 3 white ribbons at the A board, disconnect P2,P11, p35 and power up.

Should turn on and stay on and then you can probe the voltages if you wish but I'll be surprised there is anything wrong with the PSU.

Dead short on the Vsus will trigger a SOS4, but 10 blinks is also happens because of the way it's shutting down.

[andrewnelles]

Re: Panasonic tc-p50g25 10 Blinks

Thanks for the quick reply. Measuring across the 2 pins at SC2, I get about 2K ohm and it rises about 1K per second after that. Similar results across P2.

With P2, P11, P35, and the 3 ribbons disconnected. It will power up just fine, and stay on for about 20-30seconds, after which it shuts down and gives me 4 blinks.

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

Great, now i may have to eat my words.

You're the first one I've seen posted with a SOS 4/10 that did not have shorted SC2.

As for having all that disconnected and then getting sos4 after 20-30 secs that's a curve ball.

I must admit i have tried it once on mine and got normal start-up but did not let it run that long. That may be normal with no load?

Going back to SC2, how high did resistance get? I can get 300K ohms on first probe and then if i lift off a probe and put it back on it goes Mohms.

How good is your meter?

I still suspect SC. Q661 is one transistor that commonly goes short across the 3 pins if you want to quickly check that one.

Or start checking all the IGBTs on the heatsinks for short. part number i've seen short are,

Q16402 DG502LW
Q16403 DG502LW
Q16421 DG402RP
Q16422 DG402RP
Q16661 RJP63F3A
Q16441 45G128

delete the "16" for id on the board itself.


It is possible it's shorted but SC2 is low but not dead short.

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

Ok, if my wife found this out she'd kill me. I just messed with my V20, SOS4 does trigger after a 30secs or so. My TV is 100% good, hope it still is when I connect it all up again.

Focus on the SC. good you pointed that out, we just learnt something.
Thought it was strange.

On my X20 which is a HD model and had an interconecting cable between the SS & SC it just keeps on running which is the model I've first tried that on with it running for a while.

So situation normal i say.

[andrewnelles]

Re: Panasonic tc-p50g25 10 Blinks

I was thinking the shut down after awhile might be normal as well, probably detected nothing was hooked up.

SC2 creep up to about 6K and then slows to a halt. If I lift up and recheck, it has crept down a bit, and returns to climbing.

Q661 gives me the following

G-E = 11ohms
E-C = Short
G-C = 11ohms

My meter is an older Tenma portable meter. 72-045 is the model.

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

And the good news, my TV still works

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

I was thinking the shut down after awhile might be normal as well, probably detected nothing was hooked up.

SC2 creep up to about 6K and then slows to a halt. If I lift up and recheck, it has crept down a bit, and returns to climbing.

Q661 gives me the following

G-E = 11ohms
E-C = Short
G-C = 11ohms

My meter is an older Tenma portable meter. 72-045 is the model.

Well the short is a giveaway but for what it's worth

G-E 2.2K
E-C over 100K, keeps charging
G-C over 100k keeps charging

in diode

G-E .64, .86
E-C .4, hit 2.0 then meter quits
g-c 1.1, hits 2.0 then quits

thats both polarity results. Either way SC is dead

click on my profile, statistics, threads started, TNPA5081 rebuild, go towards the end and download the 2010 FHD G20/G25 series hand book for the buffer board tests.

real late like 1.40am here so can't hang around much more

[andrewnelles]

Re: Panasonic tc-p50g25 10 Blinks

Thanks for your help!

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

Thanks for your help!

I don't know what your skills are or how you want to tackle this but if you check each IGBT on the heatsinks and post up the bad ones I'd be interested to see how blown this board is.

I have repaired 3 SC boards but no one yet has reported repairing theirs with any of my info.

Anyway it all depends if you like a risk but is possible to repair pretty cheap but there are some traps which you'll discover if you read through the whole thread. It was very satisfying in the end.

[andrewnelles]

Re: Panasonic tc-p50g25 10 Blinks

Went through the IGBTs you listed, definitely some issues there. Most checked out ok, but a few were giving what appeared to be abnormal values, and a few shorts encountered.

I need to get this TV up and running asap, so I'm just going to buy a used working SC board off ebay. Hopefully that squares it away.

I had some more time I'd experiment with a repair.

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

Went through the IGBTs you listed, definitely some issues there. Most checked out ok, but a few were giving what appeared to be abnormal values, and a few shorts encountered.

I need to get this TV up and running asap, so I'm just going to buy a used working SC board off ebay. Hopefully that squares it away.

I had some more time I'd experiment with a repair.

Test those buffers before final install. Good chance they're ok, from most of the repair results i've read.

I unfortunately was a victim of a bad set and destroyed a brand new SC board being lazy.

If buying second hand board, you know what to check to see if it's ok. I've received 2 shorted SC boards from "tested working" sellers on ebay.

never installed either and fortunately got refunds.

Hope you find one, I did not see anything and Moduslink is a good price when you see how much people are trying to charge for USED. At least with a repair new parts will be installed.

[andrewnelles]

Re: Panasonic tc-p50g25 10 Blinks

Will check out the buffers, thanks again.

[andrewnelles]

Re: Panasonic tc-p50g25 10 Blinks

Checked both buffer boards as directed by the document you mentioned. All resistance values near SU41 and SD42 were near what was listed. Definitely far from a short.

TPSU16 and TPSD28 were both around 220K

The rest were all a few meg ohms. A few with creeping values.

Only hitch I found, TPSU18, wasn't registering as a ground. I ended up measuring off the metal surrounding the screw point.

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

Checked both buffer boards as directed by the document you mentioned. All resistance values near SU41 and SD42 were near what was listed. Definitely far from a short.

TPSU16 and TPSD28 were both around 220K

The rest were all a few meg ohms. A few with creeping values.

Only hitch I found, TPSU18, wasn't registering as a ground. I ended up measuring off the metal surrounding the screw point.

Sounds good, thats what I use for gnd, the metal plates. TPSU18 should to be gnd, next to one of the gnd plates and part of the same pad the plate is soldered to.

Just tried 2 bad SU boards i had and yeah no connection/result. maybe a flaw? never used that point, just the tabs. good pickup.

[tw2005]

Re: Panasonic tc-p50g25 10 Blinks

Just had a real close look at TPSU18, it's a separate track.

[andrewnelles]

Re: Panasonic tc-p50g25 10 Blinks

I noticed that too. So odd that on Slide 44, they show it as the probe point for reference ground. Doesn't seem to run to GND, and it doesn't appear to be a fault either. Odd.

Replacement SC board on the way, I'll report back when it arrives. Looks like I'm clear to safely install it.