WORKED FINE WHEN TURNED OFF, THEN NO SOUND WHEN TURNED ON

Unplug the sound bar for about 10 seconds.

Go back into the menu where the closed captions are and you likely will find either there or in the audio menu you have SAP selected which will blank sound on certain channels. (button on the remote for Stereo or MTS can also do this.

hi,
As you mentioned its sounds like the X buffer (Right and left) of your tv is faulty. There are two boards in your tv for driving the X plane of the plasma panel. Normally you can find these board on the top or bottom portion of the TV. . Its part numbers are Right buffer board is 6870QSC107A 6871QRH073A and Left buffer board i EAX35683901 EBR35855501. Before purchasing the boards identify which board is faulty. That you can find easily. Check which portion of the screen have vertical line in right or left side of the panel. The board for that side is faulty.
You can find these boards on the following link.

http://www.interliquidparts.com/products-page/plasma/vizio-p50hdtv10a-50-plasma-hdtv-flat-panel-xrlbt-xl-eax35683901-ebr35855501/

http://www.interliquidparts.com/products-page/plasma/vizio-p50hdtv10a-50-plasma-hdtv-flat-panel-xrrbt-xr-6870qsc107a-6871qrh073a/



If you need any more assistance feel free to contact me through fixya.
Ajin

sound more like a remote problem take the batters out and turn it on at the set and see what happens

I had a lot of problems with the same TV but i'll be watching it and it will go full volume with static and turn off by itself then i would have to unplug it from the wall. then it would work fine for a day or a week then do it again. but today it did it and it wont work the yellow light is on but wont turn on.

You can always turn your TV off, unplug it from the electrical outlet, wait for 30 seconds or so, plug it back in, then turn it back on. If you have kids check the menu options to see if they may have tampered with it unintentionally. If all else fails, call Vizio and ask for their professional help. If you are not satisfied with their help and assistance, make a complaint by going to BBB.org (Better Business Bureau). Maybe if you tell Vizio that you're going to call the BBB then they might take you a little more seriously.

Your audio switch on the back may have gotten moved please check the switch

remove Battery and then try again

IT is the Y Sustainer board blowing fuses. IT has 2 fuses. I have worked on severl of this model and the Y Sustainer board goes bad and blows the fuses.