I need ti know if you turn the platen knob with the power on is there any hasitation or is it free wheeling. if it's free then the motor belt is broke or a gear has snapped. if there is hasitation it may just need some light oiling on the bearings. turn the type off turn the platen if fills hard lightly oil both shafts at eather side of platen by side frame. hope this works

C.W.H.