I just got a '96 Warwick Flashback 5-string in a trade, and it's in great shape except for some issues with the pots (the bass is all passive). With the volume knob, most of it's travel does nothing up until the very last millimeter, where it turns the volume all the way up. It's basically on or off. With the pan pot, when at either extreme (soloing either pickup) it allows for maximum volume, but in any position of blend, it cuts out about 80% or more of my volume/output. With the tone knob, it doesn't do anything up until the very last millimeter of travel, where it lets maximum treble through. Like the volume knob, it's basically on or off. Finally, when I touch the pan knob, I get a slight electronic buzz through the amp, like a grounding issue or something. Touching the other two knobs doesn't do this. What's going on??