My controller keeps disconnecting

Hey so I'm kind of new to this, but from the reading I've been doing I might have to repair my WiFi card?

Basically my controllers keep disconnecting. The further away from the console I get the worse it gets. But basically to play a game right now I have to sit less then 2 feet away from the system with the controller facing the system (almost like it's IR based).

So do I need to replace my WiFi board?

Is it doable by a hardware novice?

And where can I get one for a decent price?