it is very complicated for non technician to repair this machine as, a lot involved.
you have to remove the belt and the servo motor at the back, remove the big wheel and remove the gear trey, than you have to remove the the four plastic two on top and two at the bottom of the circular plastic, remove the circular plastic its in two pieces, separate the circular plastic, clean them with parafin. than apply thin film of silicone grease, try to clean all the parts you removed, clean them with parafin, than put them back in reverse order.
sweethoneyfellah, October 2011