Please check the following points:

• (For models with Automatic Document Feeder only)
  Wipe the scanner glass strip with a dry lint free soft cloth.
   
• Clean the corona wire inside the drum unit by sliding the green tab.
  > Click here to see how to clean the corona wire.
   
• Make sure the green tab of the corona wire is at the home position.
   
• The drum unit may be damaged. Put in a new drum unit.
  > Click here to see how to replace the drum unit.
   
• The toner cartridge may be damaged. Put in a new toner cartridge.
  > Click here to see how to replace the toner cartridge.
   
• The fuser unit may be contaminated. Please contact Brother Customer Service from "Contact Us".