Thank you for posting your question on Just Answer! I will be happy to help you with this problem. Can you please give us some more information so I can better answer your questions.
-What exactly is the squence of events when you turn the set on? (noises, lights blinking, what happens on the screen, ect.)
-How old is the unit?
Please give me this information and I will be happy to assist you further.
There are a couple of things that can cause this. Please tell me a little more about your situation so I know where to go with my answer.
What kind of information are you looking for? Trying to fix this yourself or get a good idea of what's wrong and what it will cost?
If you are trying to repair this yourself, what kind of electronic repair experience do you have, do you know how to use a meter and solder?
Please let me know!
Well this unfortunately is not going to be a quick fix, what you have here is an internal failure causing the set to go into shut down. It can be caused by many different circuits. However troubleshooting would be require to know what is causing it for sure, then soldering would be require to repair it.
The average repair on a set like this is $250-$350 which is a lot of money to put into a tv of this caliber considering the prices on the new sets have come down so far.
I am sorry to bring the bad news, I know you were hoping for reset button or an easy fix, but unfortunately if your set is doing this and unplugging and plugging it back in don't fix it, then it will require internal repair.
If you would like any additional information or have more questions please don't hesitate to ask!
Please never accept an answer until you are 100% satisfied and feel you can leave positive feedback. If I have answered your questions and met your needs then please press the green "accept" button. Otherwise please feel free to ask anything else to get your problem resolved. Positive feedback is always appreciated! Thank you,Tim Nolan