Protron flatscreen tv remote and tv controls not working.what is extent of repair and cost?

The control chip is dead. Since the chip is on the mainboard it also must be completely replaced.
The problem is not in the price - the board and the replacement labor by a repairman will cost you less than $300 - it will be in finding the board in the first place: Protron is a no-name manufacturer that makes its tv's from separate parts that it buys from other manufacturers at the cheapest price possible, they only assemble them also the cheapest way possible; as such you can't get parts from them , they don't have any - especially if the tv is out of production for more than a year(all the warranties have expired and they no longer have to fix them). Because of that all you can do is to try to find a second hand board online or at a repair shop. Before calling a repairman make sure it can get the board at a reasonable price.