I've been searching extensively and have found little (nothing, really) that mentions a 12 blink problem on a Panasonic LCD. I've found extensive info on the Plasma's but not on my little TC-L42U25 that was given to me. I can't seem to find anything on 12 blinks, but seeing as how it only has 2 boards, I'm fairly certain its one of 'em. The power board is the MPF2941, if there's any known problems with it.
I found a number of guides on http://tsn.pstc.panasonic.com/ by searching Google, but nothing that references my model specifically. All fo the info I've gleaned so far was close, but not nearly the same, so I have no leads to follow.
The only other indicator I have of the problem is that after a moment that it starts to boot, there's a high pitch whine from the power board, then the blinks start. There's not been a picture since this issue began.
That is a link to the technical repair guide to your tv..you are right I googled till I could google no more but still did not find a twelve blink answer. it probably is the power supply but that is just an educated guess.
I have the exact TV and the exact same problem. I recently bought a new power board on ebay...didn't help...just put in an A board I bought off ebay today...didn't help. I turn on the tv and a black screen appears, then about 10 seconds later I hear a high pitched noise, the tv shuts off and the light blinks 12 times. Does anyone know what could be causing this???????
llabine1, thanks for the info. Unfortunately, as you said, it didnt tell us much about the probelm.
Mpeter86 - that is EXACTLY my tv's problem. I forgot to mention the squeal. It seems to come from the power board on mine - is that your experience on yours?
As soon as i get the chance, I will probably try to apply this fix...but I'd sure like to be closer to an answer and not just poking around with my iron hoping for good luck: http://www.youtube.com/watch?v=qQ_iLxx3Fj4
I was watching the tv one day and then it just shut off and has been unusable ever since. I replaced the power board but it still makes the noise and nothing changed. Not sure what to do now that I have 125 dollars of replacement boards in the tv and it still doesn't work. I still am unable to find anywhere what 12 blinks means...which is quite strange in my opinion.
I recently brought my TV to a repair place and had them try to diagnose what the issue was. They said that the T-CON board had a couple of blow resistors that was causing the problem. They wanted 150 dollars to repair the resistors. If you go on ebay you can buy the board for 10 dollars and that includes shipping. My board should be here Monday so I will let you know if that solves the problem. Hopefully someone is willing to buy back the other boards that are unneeded.