Phyllis I agree. If your maintenance included greasing the X-Carriage, chances are very likely that the optical sensor may have some grease on it, or the flag / surface of the X-carriage that the optical sensor is looking for may have some grease as well. There is always a chance that something else may be causing the problem, but this is something you can verify right away that can get you up and going. Something else to keep in mind,,,,, Even if you are under warranty, if the tech determines that the problem is a blocked optical sensor caused by over greasing, MELCO will bill you for it. Not to mention the $200 just for him to walk thru the door. HUGO TORBIDONI MELCO Tech AMAYAS, EMT, EMC.