If that light doesn't turn green when you attempt to power on via the remote or tv, your board is too old. TV's have a life of about 5 years these days. It's not worth replacing the board either. Costs just about as much as a brand new tv. Recommend you dispose and buy a new tv.
My best bet is it's your logic board. I've had issues with the logic board affecting other parts in the past.. this is really the only place you could remotely do any such test for free..Hardware test
