i bought mine used from ebay, which MAY have been a bad thing, but here's what happened. me and my band were rehearsing and the vibration from all the lows made the head fall off of my cab, thus breaking the master volume pot. so i take it to skips music in sacramento, california and it costs me $90 to get that fixed. the night i picked it up was the same night we had a show. so i hook up my rig and nothing... luckily, i brought my back up so i used that for the night, took it BACK to skips to get THAT fixed and it ended up just being the relay, so he fixed that free of charge. so from then on, it's working pretty good. no problems at all. one day we had an outdoor gig. probly in about 85 or 90 degree weather.so we come to the end of our set, the last song, and it just shuts off. the power is still on, it's getting signal because i can see the compression light flickering. so i tried turning it off and back on and it worked. we finished our set without anymore problems. so a few days later we have practice. halfway through the first song it does the same thing. so i thought since it was getting signal to the amp and not to the speakers, it HAD to be the output of the head, the cable, or the input on the cab, checked all of that and everything was fine. i tried maybe 3 or 4 different cables and everytime it would work for a little while and then die out. i called skips back and explained my problem and they said that it would be at least $150 to get it taken care of, if not even more. i bought the thing for 300 and im just not sure if it's worth putting that money into it, keep in mind that im only 17 years old and dont make enough money to have much extra after each payday. has anyone else had this problem and if so, what can i do to fix this? thanks for your time.