Panasonic TC-P54G25 8 blinks

[dhyde]

Hello,

My Panasonic TC-P54G25 manufactured Nov 2010 has worked great for several years. A few weeks ago it would turn itself off and the front power LED would blink 8 times. I would unplug/plug the system and it would come on and run for several weeks then shut off again. Now the set comes on and runs for 5 minutes before shutting off with 8 blinks. I researched the issue and most point to the SS board (my set uses the TNPA5082 board on the right side and the TNPA5081 board on the left side looking at the back of the set). The first step seems to be to make sure the flex cables are securely attached to the right SS board.

If you have any advice or Panasonic service guides I would greatly appreciate the help. I hate to throw away the set -- it has a great picture and up until this problem has worked great.

Thanks
dhyde

[Moreno83]

Re: Panasonic TC-P54G25 8 blinks

Could you please provide some pictures of the set? ( The boards )

It sounds like a mainboard problem deu to overheating but pictures first!

[dhyde]

Re: Panasonic TC-P54G25 8 blinks

Starting from the rear right side of the TV the images are: both SS and A board, just right SS board, just A board, power supply, left ss board and the entire left side.

I think I have the board names (ss, a...) right but I'm not sure.

The right ss board has the part number TNPA5082
The A Board (has all the video connectors) part number TNPH0834
The left side ss board part number TNPA5081

If you need more detailed pictures of any boards let me know

Thanks for your help

[Moreno83]

Re: Panasonic TC-P54G25 8 blinks

Here you have the service and troubleshooting guide.
Troubleshooting guide , page 43/44 shows 8 blink code.

It does look like a SS or A board problem! Could you try the steps provided in the manual?

[dhyde]

Re: Panasonic TC-P54G25 8 blinks

Thank you very much for this information. I will perform the steps and post the results this evening when I get home.

[Moreno83]

Re: Panasonic TC-P54G25 8 blinks

Your welcome! With a multimeter you will get some results.

The fets and diodes are marked with Q and D on all boards.
Q is a mosfet wich you can measure in diode mode , measure outer legs.
D is a diode. Black prope on middle pin and red on left/right pin. In both situations a beep is usually not good.

Also measure the prong connectors on SC and SS board in diode/beep mode. Could you also check the back of the SS board for bad solder? Maybe reflow the solder and also the ground area's ...maybe some arching happened.

There is a huge time difference so evening for you is midnight for me!


good luck!

[dhyde]

Re: Panasonic TC-P54G25 8 blinks

I followed the troubleshooting guide for 8 blinks. When I checked the connectors from the SS card to the panel one of the ribbon cable connectors seemed loose so re-seated all three (one was on the small lower SS2 board). I also checked continuity between pins 1 and 2 on the 2 connectors from SS to the panel they were ok (one was 1 ohm the other 2 ohms). Checked between pins 6 and 7 on connector between SS and SS2 and again 2 ohms (seems ok). I plugged everything up and the TV ran fine for 30 minutes or so they shut off and now shows 10 blinks.

The debug flow diagram for 10 blinks has two scenarios, one for 10 blinks at plug in and another for power on. Neither seem to fit my case since the set ran for several minutes before shutdown. Will be away from home tomorrow but I'll pick the debug back up in a day.

Thanks
David

[Moreno83]

Re: Panasonic TC-P54G25 8 blinks

Strange symptom. I would not be surprised if this is a mainboard problem deu to overheating. ( BGA Solder problem ).
Why do i think that? The parts on the SS / SC board / PS either work or dont work.

I think that the CPU is overheating causing the set to shut down with a blink code. Follow the chart for 10 blinks and see what happens. If you get weird results from the tv that dont match the troubleshooting guide then i would replace the mainboard.

Also check on all boards if the screws are tightened and all grounding is ok.

[Moreno83]

Re: Panasonic TC-P54G25 8 blinks

https://www.badcaps.net/forum/showthread.php?t=57049

Follow these steps as well and also check for cold solder on all boards.