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 is the model number for the television? (this can be found on the back of the unit)
-How old is the unit?
Please give me this information and I will be happy to assist you further.
There are a couple of different things that could cause this problem, the first is the power supply, and the second the main board. Also either sustain or scan driver board can cause this problem. To know exactly what board is the cause, you need to have electronic repair experience, and test equipment. If you have this let me know and I will assist you in the troubleshooting of this tv. Otherwise you will need a repairman at this point. You can expect a bill of anywhere between $200-$400, this is a good average, however it could be more or less.
I am sorry I don't have a quick fix or easy answer for you on this one, please let me know if you have the skills and tools and I will be happy to assist you. Also please let me know if there is anything else I can do for you.
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
Sorry to give you the bad news, let me know if you need anything further. Unfortuantely your set has an internal failure.