Service manual

1-21
Confidential
4. IMAGE DEFECT TROUBLESHOOTING
4.1 Image Defect Examples
Fig. 1-5
4.2 Diameter of Rollers
Image defects which appear periodically may be caused by failure of a roller. Specify the
cause referring to the diameter of the rollers or pitch which appears in the image as shown in
the table below.
No. Parts name
Diameter
The pitch which
appears in the image
1 Develop roller
Ø20.0 mm 41.0 mm
2 Exposure drum
Ø24.0 mm 75.0 mm
3 Heat roller in the fuser unit
Ø25.0 mm 78.5 mm
4 Pressure roller ASSY in the fuser unit
Ø25.0 mm 78.5 mm
Light
Poor fixing
Dirt on the back of paper
White vertical
streaks
Faint print
Black spots
Downward fogging
of solid color
Horizontal lines
Ghost
Fogging
Black band
White spots
White horizontal
streaks
Vertical streaks
Black vertical streaks
in a light background
Black horizontal
stripes
Completely blank
Image distortion
All black
Faulty registration
Dark