If your printout has dots or other repeating marks at 94 mm (3.7 in.) intervals, the drum may have foreign material, such as glue from a label stuck on the drum surface. Follow the steps below to clean the drum unit.

1. Open the front cover.
   
    
2. Remove the toner cartridge and drum unit assembly from the machine.
   
    
3. Push down the green lock lever and take the toner cartridge out of the drum unit.
   
    
4. Turn the drum unit as shown in the illustration. Make sure that the drum unit gear is on the left side.
   
    
5. Turn the edge of the drum unit toward you by hand while looking at surface of the suspected area.
   
    
6. Wipe the surface of the drum gently with a dry cotton swab until the mark on the surface comes off.
   
    
7. Put the toner cartridge firmly into the drum unit until you hear it lock into place.
   
    
8. Install the toner cartridge and drum unit assembly back into the machine.
   
    
9. Close the front cover of the machine.