| Re: Guitar fault
My bass did that to me a few months ago when i changed the battery. When it was plugged into the amp the sound came and went, plugged into the 4 track it was fine. The problem vanished as quickly as it had arrived, never figured it out.
My acoustic doesn't have a battery, that confused loads of people one night when all that was wrong was a loose wire. For 30 minutes i had people saying "it's the battery", "of course it needs a battery" and quieter "haha, he doesn't even know his guitar takes a batter". I eventually thrust it towards one of the guys, he looked at it and said "oh, it doesn't use a battery". | 
