Last October I bought a brand new Mesa/Boogie Mark IV head and I love it. But last friday I had a gig and the footswitch thought it would be fun to stop working at the show. It was working fine an hour before the show because i was warming up and it was fine. No wires were cut and it wasn't mistreated or anything so I dont know what happened? Any ideas on whats wrong with it and how to fix it?