My Mesa/Boogie Walkabout combo dies this morning and I have no idea what happened or what to do. My 6 year old son wanted to "jam" and all was fine. I then plugged into my Boss ODB3 (without turning off the amp) and . . . nothing - no sound at all coming out of the amp. I shut off the amp, disconnected the pedal, and plugged directly back into the amp. Again, nothing. The amp turns on, but produces no sound at all. Any thoughts on what happened and what needs to be done to fix the problem? Thanks in advance - this is the first time something like this has happened and I admit to being a bit freaked out.