I have a Samsung PN50A450 with no picture. It has sound and turns on and off normally it just has no picture.

backlight inverter or tcon board

Try this web site for PDF of things to check

I would suspect a problem with x main board or circuit. I would start with checking the connections on the x main board?

hi this sound like a capacitor could have blown or bulged up could you put up a picture of the power board i'll take a look for you

regards
shaun

check to see if all closed captions are turned off

This sounds like a software problem in the circuit board for picture processing. take it back to the store and get a replacement.

Y board, Y-buffer board, or panel can cause this problem. Anyways, replace the panel shall be good, because those boards will come with the panel.

I have a Samsung Plasma PN50A450 and one night the TV turned off and the result of trying to turn it back on was simply the set trying to turn on, making a click sound and nothing happened. I pulled the back off, and attempted the capacitor fix that is well documented on the Samsung LCD TVs. I did have a swelled capacitor that I replaced and also replaced the other capacitors that were the same Microfarad rating, temp and voltage which were replaced in a popular UTube video. That did not solve my problem, so I went onto Ebay and bought an entirely new power board for 69.00 plus 14.99 shipping. Replacing the board took about 3 minutes. TV is now working fine and will go back up on the wall in a day or 2. Note, the power board in my TV was a BN44-00205A. That board is no longer in stock anywhere ( I believe because it has been determined to be a bad board) I replaced it with BN44-00207A. Which I suspect is the board that is being used for replacements of the bad BN44-00205A. It fixed My TV. Hope this helps you. BTW, Both power boards are listed for replacing a board in the PN50A450, but the BN44-00207A Specifically states its for a PN50A450P1D. I took a gamble that the BN4400207A would work. It did.

first unplug it for 10 min then retry it. otherwise it is the power supply, the low voltage and high voltage supply are on the same board, have your tech send it in to be rebuilt if he is unable to do it him or her self.

This is a problem in one or more boards in the TV.
If your TV is still under warranty please call Samsung to get if fix at not charge.
parts for your tv are not cheap and labor is not eider.