Clean the inside of the printer (scanner window) as follows:

1. Turn off the printer power switch, and then unplug the printer.

2. Press the cover release button and then open the front cover of the printer.

   

3. Pull out the Drum unit assembly.

   

   Some internal parts of the printer are extremely hot. Never touch the parts marked in red.

   

4. Gently wipe the scanner window with a soft dry cloth.

   

5. Put the drum unit assembly back in the printer.

   

6. Close the front cover.

7. Plug the printer back in, and then turn on the printer power switch.

   If the problem is not solved after printing a few pages, the toner cartridge may be damaged. Put in a new toner cartridge. To see how to replace the toner cartridge, click here.