Thanks for the question. My name is Dan.

Just a couple questions so I can get a better idea about what's going on here.

1. How old is it?
2. If you're outside warranty, do you want to repair this yourself? Do you have experience? Tools? Or are you just trying to figure out it's reparable?

Respectfully,
Dan

The first thing we need to do is remove the TV's rear panel. Be sure the TV is unplugged first. Now trace that power cord to a circuit card inside the TV... that's the power supply. Have a good close look at the board, paying particularly close attention to the capacitors. Are any of them puffy on top, like the ones in the picture below (red arrows)? Note, this is not a picture of your TV... just an example of puffy capacitors.

Now we need to measure the voltages coming off of that power supply board. They're DC. Use any exposed chassis metal for ground. Put your leads in place and turn the TV on just incase they drain quickly. Let me know if the board is putting anything out.