Panasonic 12 blink repair on TH-P46S10

[BigPete]

Just thought I would post this repair here just in case someone may find it useful.
I picked up a TH-P46S10Z Panasonic Plasma TV with a 12 blink code.
There was only 1.6V on the 15V sound line going to the A Board. Even with the A Board disconnected there was 0V.
The A Board appeared to have no shorts on it.
I also had a spare power supply from the 42 inch version so could could confirm the A Board was fine.
The P Board, ETX2MM747, had no obvious shorts.
I measured the voltage on Q355, both the gate and source pins had 21V. The drain pin had 0V
It was a 2SJ651. I swapped it out with a 2SJ657 that I had.
Tv powered up fine
Interestingly the original mosfet had no thermal paste between it and the heat sink. The new one does. Using my meter on diode test mode, the old one was leaky.
Hopefully this will help someone in the future.

[VastSky]

Re: Panasonic 12 blink repair on TH-P46S10

Hey BigPete! Glad you repaired your P Board. It is interesting that the 12 blink was not the A Board.

I have the same P Board in a TC-P50U1. Troubleshooting guides for my blink code "1" narrow it down to a faulty P or A board.

After the set fails to turn on and displays the 1-blink, I can get it to turn on by holding in the set power button for 5 seconds, release, repeat until the set restarts normally. Once on the set works perfectly.

"There was only 1.6V on the 15V sound line going to the A Board" Is there an easy connector or test point at which to verify this?

Just trying to determine which of these two boards I should focus on.

Thanks!

[BigPete]

Re: Panasonic 12 blink repair on TH-P46S10

Hi,
Sounds similar to my problem only my TV wouldn't turn on what so ever.
With the TV trying to start, the outside pins were over 20v on Q355. The inside pin was low.
It's a P channel mosfet. Yours could be less leaky than mine was.
Be careful while testing it.