I have strong oscillations - vibrations when the roll paper is fed into the Epson SC-T2100 plotter. The ATC motor and gears look neat. The plotter starts feeding back and forth and after 5 seconds strong vibrations of the spindle roll paper begin. A4 paper feeds normally on the ASF unit and prints. I suspect the main board, Vref terminal voltage controller ATC roll paper motor? ATC and PF motor encoders are clear.