You can repair it yourself, most likely. Gotta take off the back cover and open it up. There are 3 main things in it and you can replace each pretty easily. Go online and see if you can figure out which one has gone bad. Then open it up, identify the bad board and order a new one, likely off ebay and install. The boards are just held in by a couple screws and some snap in cables. The hardest part is opening up the tv.
Also, they seem to source parts from different suppliers, so you can't just use your model number and order the board. You have to open it up and properly identify the board your tv has.
All this to say, just buy a new one.