I borrowed a used Boss pedal from work to see if I might be interested in it. First thing when I walked in the door, my dog jumps up, and I drop the pedal. Normally, that wouldn't be a problem, but this one has one of those little concentric knobs. The top, inner portion broke off. Where can I turn to get this fixed? I think I'm going to keep the pedal regardless, but it's the "Balance" knob that broke, and I like being able to mix the clean and effected signal. Does Boss repair secondhand pedals? Should I just glue it back in place as best I can? Is there somewhere I can get one of these little pots and replace it myself?