Troubleshooting For Print Image Defect; Image Defect Examples; Diameter Of Rollers - Konica Minolta Bizhub 20p Service Manual

4. TROUBLESHOOTING FOR PRINT IMAGE DEFECT

4.1

Image Defect Examples

Light
Image distortion
Black vertical streaks
in a light background
White spots
Ghost
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.
1 Develop roller
2 Exposure drum
3 Heat roller in the fuser unit
4 Pressure roller ASSY in the fuser unit
5 Registration roller
6 Transfer roller
Faulty registration
Dirt on the back of paper
All black
Black horizontal
White vertical
stripes
streaks
Black spots Black band
Fogging Hollow print by
condensation
Parts name
Dark
White horizontal
streaks
Downward fogging
of solid color
Fig. 3-5
Diameter
20.0 mm
Ø
30.0 mm
Ø
25.0 mm
Ø
25.0 mm
Ø
14.0 mm
Ø
15.2 mm
Ø
3-32
Poor fixing Completely blank
Vertical streaks
Faint print
Horizontal lines
The pitch which
appears in the image
42.5 mm
94.2 mm
78.5 mm
78.5 mm
44.0 mm
48.2 mm
Confidential