Image Problem: Black Horizontal Lines.

Trouble Shooting

StepCauseSolutionParts
1Dirt on the drum unit charger.Clean the charger of the drum unit (see below).  
2Drum unit defective.Replace the drum unit.Drum (015-0289-21)
3Scratch or dirt on the develop unitReplace the develop unit.Develop unit (015-0204-21)
4HVPS defective.Replace HVPS.HVPS (005-3141-9-SP)

Clean the charger of the drum unit.

Slide the corona wire to the end and then back to the original place. repeat this for at least 3 times.