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.
-Any problems with the tv before this? (taking longer to come on, picture issues, shutting off, etc.)
-Any storms or poewr issues lately?
-How old is the unit?
This is a very common problem with your tv, what has most likely happened (about 99% of the time) is the power supply has failed, more specifically there are a few caps in the power supply that have most likely failed. The unit will require component replacement to get it working again. Do you have any electronic repair experience, test equipment, and soldering equipment? If so I can assist you with this repair. If you do not have the above equipment and skills a repairman will be required for this repair, you can expect the bill to be around $175-200.
I am sorry that I don't have a magic button or a quick fix for you on this one, but component replacement will be required.
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