Chosen Solution
After watching for some time the screen will go black but the sound continues. Turning it off and letting it sit for a while it comes back on and does the same thing.
rghoch obviously something overheating. Could be a power MOSFET as well as bad capacitors etc. You should tell us the exact model number so we can check to see if that is a common error on your model. It might also help if you post some high-res images of the boards inside your TV with your question so we can see what you see. Use this guide for that.
My tv has picture but left side of picture is normal but right half is dim what is the fault on this.
