The drum unit may be at it's end. There is a report you can print that will say "Drum" life at the bottom of the page. I think it's the "User Settings" or something. Though it sounds like you can't print to find this out anyway....Do you recall how many times you've changed the toner without changing the drum? Usually you can expect about 4-5 toners on every drum. Once the drum's photo sensitive coating wears off it is incapable of charging correctly to print. Might just be time for regular maintenance. email@example.com with questions.