PICTURE FLICKERS ON & OFF & THEN GOES OUT. SOUND STILL ON. TH-50PX75U PLASMA TURN OFF FOR AWHILE & IT MAY WORK FOR AWHILE BUT WILL START AGAIN.

That is a power suuply problem,i have the same problem i looking for a solution to fix my or i gonna buy a new one,also new onw is spensive on ebay some people offer the repair service good look

Unplug the power cord. Press and hold the power button for 30 seconds, repeat. Plug it back in and try to turn it on.
If this doesn't work, it would be time to call in a repair tech. Is the TV still under warranty? Extended warranty?

The tv power supply board is the causes and the problems.That the board,where the power a/c cord plug into it.Try website like Ebay.com to buy a refurbish power supply board for the replacement.

tv turned off and will not turn back on. help.

There are several possibilities here. Four different boards are involved in the horizontal scan of a plasma tv. The most likely order of failure for what you describe is; SC board, Su and SD, and finally the SS. These are Panasonic's names for what are more commonly known as the Y Main (or Y-Sus), the upper and lower Y buffer boards, and the Z main (or Z-Sus). Sorry I can't boil it down any further for you,... would have to measure voltages, etc.

I have a Panasonic Plasma Tv, Model #TH-50PX75U and it will not power up. What can I do to fix this problem?

Check the power plug,check the power outlet.Change ur power supply board is dead.

Go here for the download
http://www2.panasonic.com/consumer-electronics/support/Televisions/VIERA-Plasma-HDTVs/model.TH-50PX75U

Are you using component video cables? If so, check that these aren't loose on either end. Next I'd consider that whatever video cable/input might be bad, and switch cable or cable type... i.e. switch from component to HDMI or vice-versa. Then change up the source (cable box versus DVD player). If you're still seeing blue at this point, the TV internals are the bad.