Fuji Xerox ApeosPort-VII C7788 Quick Reference page 242

7 Problem Solving
Symptom
Black dots are
printed.
Black or colored
lines are printed.
Dirt appears at
equal intervals.
Paper Feed
Direction
242
Cause
The drum cartridge has
deteriorated or is damaged.
The drum cartridge has
deteriorated or is damaged.
The constant velocity
transport glass on the
document feeder is dirty.
The paper path is dirty.
The drum cartridge has
deteriorated or is damaged.
Remedy
Replace the drum cartridge with a new one.
Replace the drum cartridge with a new one.
Clean the constant velocity transport glass.
Print a few pages to remove the dirt.
Replace the drum cartridge with a new one.