Kyocera FS-720 Service Manual page 64

2GL/2FV/2FW
(9) Dirt on the top edge or back of
the paper.
ABC
123
Causes
1. Toner contamination in various parts.
2. Defective transfer roller.
(10) Undulated printing at the right
edge (scanning start position).
This vertical
line should
be straight.
Causes
1. Defective laser scanner unit.
2. Defective engine controller circuit in the
engine/high voltage PWB.
1-5-22
Causes
1. Toner contamination in various parts.
2. Defective transfer roller.
Check procedures/corrective measures
Dirty edges and back of the paper can be caused by toner accumulated
on such parts as the paper chute, paper transportation paths, the bottom
of the drum and developer, and the fuser unit inlet. Clean these areas
and parts to remove toner.
If the transfer roller is contaminated with toner, clean the transfer roller
using a vacuum cleaner or by continuously printing a low-density page
until the symptom has faded away.
Causes
1. Defective laser scanner unit.
2. Defective engine controller circuit in the engine/high voltage PWB
Check procedures/corrective measures
Defective polygon motor in the laser scanner unit. Replace the laser
scanner unit. See page 1-6-20.
Replace the engine/high voltage PWB. See page 1-6-17.