I had the strangest thing happen last night. My Boss MT-2 cut out and wouldn't let any signal thru when the pedal was engaged (led was on) yet it would let signal thru just fine if the pedal was turned off (i.e., clean). I grabbed 2 other Metal Zones and had the same thing happen... at first they worked like normal and then all of the sudden... nothing (turn the pedal on and no sound, turn it off and the clean signal passed thru). A little bit later they seemed to work fine. I checked my cables, amp, guitar volume, etc. to make sure it wasn't anything stupid.
Now the only thing that I can think of (and this is a BIG stretch) is that I already had the pedal hooked up (guitar > pedal > amp) when I plugged the 1-Spot power supply into the back of the pedal and I have seen before where if you touch the power supply jack to the housing of the pedal (i.e., it's metal case) then the pedal can cut out (had this happen on a few pedals on my pedalboard when replacing/replugging in the Boss daisy chain power cable while I was "live" from the guitar to the amp. I always figured it was something to do with the metal pedal case being grounded and the power supply was "hot" and it was shorting out when the 2 touched. Take the power cable off the pedal's metal casing and all worked again normally.
However, last night it when "dead" while the power cable was correctly plugged into the back of the MT-2 (and it worked fine as long as the pedal was in bypass mode).... Hmmm.... very strange! As I said, later it all worked correctly again but the fact that it seemed to happen to 3 different MT-2 (and no other pedals - I was testing my pedalboard so at various times I had multiple pedals in/out of the signal path)... it all makes me wonder if this is some freak thing with the MT-2 that I've never heard of before. Anybody got any ideas?!?!?!