2-73
Confidential
 Spots or dirt
<User Check>
• Check if damp paper is used.
• Refer to <How to clean the drum unit> to remove the dirt from the 
exposure drum using a cotton applicator.
• Replace the drum unit with a new one.
• Replace the toner cartridge with a new one.
Step Cause Remedy
1
Dirt on the paper dust 
cleaning roller of the paper 
tray
Refer to the Fig. 2-10 (P2-53) to clean the 
paper dust cleaning roller.
2
Dirt on the exposure drum Perform drum cleaning.
(Refer to “2.2 Drum Cleaning” in Chapter 5.)
3 Clogged filter Clean the filter.
4
Scratch or dirt on the fuser 
unit
Replace the fuser unit.
5
High-voltage power supply 
PCB failure
Replace the high-voltage power supply PCB 
ASSY.
Note:
Image defects which appear periodically may be caused by failure of rollers. Refer to 
<Pitches on images caused by rollers> and determine the cause based on the pitch at 
which defects appear on the image.