Panasonic TC-P42GT25 8 blinks

[freelancenoob]

I have a panasonic on the bench now. 42" 3d plasma. It turned on and worked perfect for 10 minutes. Then the tv shut off and started blinking the red power light. Blinks 8 times then pauses. Can not turn the tv back on until I unplug the system and wait a little bit. Then same process all over again.

I went by this troubleshoot
https://www.manualslib.com/manual/83...page=17#manual
8 blinks says to check SS & SS2 board.

[AnthonyC]

Re: Panasonic TC-P42GT25 8 blinks

This manual helped me out on mine (P50G25). It's for the G series, not GT, but I imagine much of the troubleshooting steps are similar.

[Moreno83]

Re: Panasonic TC-P42GT25 8 blinks

Usually the SCBoard goes defective on these models.

Did you tighten all screws? Normally when a SS or SC board goes defective it stays defective ( FETS shorted for example ).
This could be a BGA problem on the mainboard. Tv turns on , board gets hot , solder gets loose and board thinks there is a problem with the tv and shuts down.

Tv is probably fooling you with the blink code.

[freelancenoob]

Re: Panasonic TC-P42GT25 8 blinks

https://www.manualslib.com/manual/11...?page=2#manual

Found this manual also. Its the correct one for my tv and not the one I posted in the original post.

Usually the SCBoard goes defective on these models.

Did you tighten all screws? Normally when a SS or SC board goes defective it stays defective ( FETS shorted for example ).
This could be a BGA problem on the mainboard. Tv turns on , board gets hot , solder gets loose and board thinks there is a problem with the tv and shuts down.

Tv is probably fooling you with the blink code.

I'll go through and make sure all the screws are tight and see what happens.

[freelancenoob]

Re: Panasonic TC-P42GT25 8 blinks

While I was tightening screws I decided to do a continuity test on a few things. No power to the system I get pass through on 2 of these chips. Rest all have resistance. Swapping probes around gave same results. Does this mean anything?

[dick_barton]

Re: Panasonic TC-P42GT25 8 blinks

Do you have 0 reading between the middle pin and either or both of the outer pins?

[freelancenoob]

Re: Panasonic TC-P42GT25 8 blinks

Do you have 0 reading between the middle pin and either or both of the outer pins?

All the readings are from outter leg to outter leg. I just went back and put negative on center leg of each one. I can only get a reading on center leg and right outter leg on those that gave a value. That reading is just about 300. Now on the 2 that gave 0 i can touch center to right and get little over 300 and i can also touch center to left and get same reading.

[dick_barton]

Re: Panasonic TC-P42GT25 8 blinks

What are the part numbers on them?

[tw2005]

Re: Panasonic TC-P42GT25 8 blinks

All normal and the ones in question are diodes

[tw2005]

Re: Panasonic TC-P42GT25 8 blinks

any arcing sounds (crackles)? may be worth pullings the boards and removing any dust build up. Could be a long shot. Visually I don't see what I'm looking for but I had a 65" 2009 which did something similar. Heard arcing on the SS, turned the lights off and I could see it jumping from the board to chassis.

The large blue polyester caps were failing, had cracked and as it warmed up arced and 8 blink.

But could be a false detection and A board could be letting go with heat, tough one.

I think you would need to find the SOS8 line and see if it's changing level at the same time it shuts down the TV.. If the SOS 8 line is not coimanding the A board to shutdown then very well be the A board.

Can't comment from experience on this one. SS boards may be cheap enough if you want to gamble

[tw2005]

Re: Panasonic TC-P42GT25 8 blinks

Mrs reckons I keep too much crap. I strongly resent that accusation.

Oh, found the cap, LOL Now I've picked at it and pulled it apart a bit but it was cracked and swollen

[freelancenoob]

Re: Panasonic TC-P42GT25 8 blinks

I found TPSOS8 in the bottom right corner of this photo. Is that the one you speak of? I pulled this from an ebay photo identical to my board. I have a board that overlays this board so I haven't taken it that far apart yet.

[tw2005]

Re: Panasonic TC-P42GT25 8 blinks

yeah, good spot to start. Don't remember if it's a high or low that triggers. Probably fin in a training manual for that series it'll run you through checking this anyway. you'd have to have a look. Any 2010 series trainer will do

[tw2005]

Re: Panasonic TC-P42GT25 8 blinks

I don't much more time, see where this takes you.

[tw2005]

Re: Panasonic TC-P42GT25 8 blinks

That could be wrong slide, better check this one first. grabbed the other in a rush

[freelancenoob]

Re: Panasonic TC-P42GT25 8 blinks

TV powered on that pin has no voltage. Waiting for tv to warm up and shutdown with the blink code to check it again.

[freelancenoob]

Re: Panasonic TC-P42GT25 8 blinks

Now the blink code is back and still no voltage on that point.

[freelancenoob]

Re: Panasonic TC-P42GT25 8 blinks

Well I followed the second diagram. I unplugged ss33 and powered on the tv. Tv stayed on but I had no video. So I did both options. I checked all connections and they were all fine. I checked continuity on the 3 connections that connect to the ss board. Those all checked out. Since the continuity checked out it tells me to replace the ss board. But since the tv powered on but no video does that mean my A board needs replaced?

[Moreno83]

Re: Panasonic TC-P42GT25 8 blinks

When either the SS or SC board fail the tv wont turn on AT ALL! Unless a bad cap as TW2005 said. A shorted diode or FET stays shorted.

My guess is a bad mainboard! Especially as the tv shuts down after a while....that is heat causing the problem. Can you touch the mainboard or is it to hot to touch

[tw2005]

Re: Panasonic TC-P42GT25 8 blinks

Well I followed the second diagram. I unplugged ss33 and powered on the tv. Tv stayed on but I had no video. So I did both options. I checked all connections and they were all fine. I checked continuity on the 3 connections that connect to the ss board. Those all checked out. Since the continuity checked out it tells me to replace the ss board. But since the tv powered on but no video does that mean my A board needs replaced?

Depends, You say it does not 8 blink straight away. so was it on long enough to prove anything?