Panasonic TX P50X50B red led flashes 14 times

[RNRepair]

Hi, hope someone can help me with this. Customer watching through USB stick then suddenly heard crackling, the screen went blank, and set stops responding to the remote. Now the set tries to come on but then red LED blinks 14 times. Very similar to this post:
http://www.tv.quuq.org/forum/index.php?topic=7463

Another thread mentioning 14 red blinks
http://www.tv.quuq.org/forum/index.php?topic=6737

Following the advice on the above threads, I've just replaced the A-Board (TNPH1002-1-A).
But there's no change: red LED blinks 14 times.

Any help is very much appreciated.

[RNRepair]

One last thing that's worth mentioning is that when the set was first switched on (both after the fault first happened, and after the A-Board was replaced) the green led blinked very quickly 4-5 times and then went steady green. Only after switching the set off and on, using the set's POWER button, the red LED started blinking 14 times.

Once again, any help much appreciated.

[downunder]

A flashing green standby LED is normal start-up procedure on these, then, if it detects a fault, it goes to flashing a red code. Code 14 is definitely an audio SOS and all the audio is on the A-Board. So, was it a brand new board, or an unknown stripped from a wrecked TV.

Also, although I've never found it to be so, check the speakers for shorts and check that the speaker wiring isn't pinched under some metalwork. Most likely cause is IC4510 which controls the HDMI and the 15V B+ for the audio PWM.

Unfortunately, the A-Board is not very repair-friendly, but my money is still on this board.

Bruce (again)

[RNRepair]

Thanks downunder for your advice. I'm going to find another A-Board, and will report as soon as.

Re green LED flashing at startup: The normal start-up green flashing (when the TV was working fine) is relatively slow. But the green flashing I was referring to (when the TV developed this fault, and after replacing the A-board) was very fast, and was not followed by red diagnostics blinks, but by a steady green. Only after using the ON/OFF switch on the set itself, did I get 14 red blinks (and no green LED at all at startup!).

[RNRepair]

I've replaced the A-Board again (as per downunder's advice), but still getting 14 red flashes 

The 2nd board was new from a set which was delivered new with broken screen, so I'm pretty sure the problem is not the A-Board.

Is my only option to have every board replaced?

Any help very much appreciated.

[downunder]

Hey, sorry if I've given you a bum steer, RN. Like you, I was convinced that only the A-Board could cause it.
It may of course be a false code.
Do you still get code 14 if you disconnect the SN board from the power supply, otherwise I'm at a total loss.
This is the only bulletin I can find for this model but it doesn't sound like your problem.

Bruce

[RNRepair]

Hi Bruce - no worries re A-Board. We live and learn.
Still getting code 14 after disconnecting power from SN board.
Could it be that power board is faulty? supplying power to parts of the set, but not to others?
Could the IR or Buffer boards be faulty?
Is my only option to replace all boards one at a time?
Thanks again for your help - Roy

[RNRepair]

one last shot in the dark: is it possible for the power board to be faulty in such a way, that when the A-Board is replaced, the power board causes immediate damage to it (the A-Board)?