I bought this amp in 1998, A few years into it and started developing this power oscillating sound. It would be fine and then all of a sudden it would give me a pulsing sound and my bass would be distorted. It happened at a couple shows, so eventually I just purchased a new bass amp, I was young and wanted a monster amp anyway. Anyway I recently started playing keyboards in a band and I started using that old bass amp, I hooked it up and it seemed fine but after an hour or two of playing organ through it, it started doing that pulsating and distorted sound again. I can't seem to get the head out of the combo to look at, it is held in with 30 invisible screws made of kryptonite apparently, but I was wondering if anybody knew what this problem could be from. The distortion makes me think that it's probably a short and maybe that could explain the warbling pulsating sound as well, but I really have no idea about repairing bass amps somebody help me out please, If I can't get the head to work that's fine, I've been using the speaker part of this combo on it's own for years now.