Please check the following points:

• The drum unit may be damaged. Put in a new drum unit.
  To see how to replace the drum unit, click here.
  
  
• The toner cartridge may be damaged. Put in a new toner cartridge.
  To see how to replace the toner cartridge, click here.
  
  
• Make sure that you use paper that meets our specifications. 
  To see what kind of paper you can use, click here.
  
  
• If you use label sheets for laser printers, the glue from the sheets may sometimes stick to the OPC drum surface. Clean the drum unit.
  To see the steps to clean the drum unit, click here.
  
  
• Do not use paper that has clips or staples because they will scratch the surface of the drum.
  
  
• If the unpacked drum unit is in direct sunlight or room light, the unit may be damaged.