I had someone call me on a old xerox 314 with a u1 error code. From what I can tell the paper will pull out of the tray about a inch then the copier codes out. It does it from both trays and bypass. According to my info u1 is a main motor problem. My question is what does the motor turn. Will a bind in the fuser or cleaning unit cause a u1 code? I will try to sell a newer machine if the motor needs replacing.