Do you have spots or streaks on your copies?
Have you cleaned the main glass and/or the slit glass?

Are you having frequent jamming?
Have you fanned the paper before loading it?
Is the paper moist?
Did you load the paper with the arrow on the label pointed down?
Is the paper loaded properly?
Are the paper guides up against the paper in the drawers?

Is there a service code on the display panel?
Have you opened and closed the front main cover?
Have you turned the machine off and back on?
Write the code down before you call for service.

Are your copies light?
Is the toner light on?
Have you pressed the add toner button?
Is the paper in the machine fresh?