The MB212 combo is displaying a weird problem with the switch. At first, the switch used to stay stuck in the on position, and would not turn off. So, I went along with that for about a month, and then the amp would switch on, and I'd hear a clicking sound, and it would switch off almost immediately. I'm currently using something to hold down that switch as a temporary solution, but I was wondering if this problem sounds like an electrical problem or more of a mechanical problem in the switch itself? Thanks guys!