Was at rehearsal a couple of weeks ago, walked a few feet to adjust something on the mixer, returned to my rig, and no sound. Checked all my cables, volume pedal - everything plugged in and set properly. Total mystery? Noticed after some more fruitless investigation that my cable was in suspiciously close proximity to my volume knob, with a small loop that had not been there prior to my circuitous trip to the mixer. And yup, the volume was at zero. The cable had managed to wrap around the volume knob and crank it all the way down through simple friction and at the risk of anthropomorphizing, a perverse sense of humor. Moral of the story, even when it's not the cable, it's the cable.