Gestetner B147, Service Manual

Page: 271 / 1081

TROUBLESHOOTING GUIDE
B147/B149/B190 4-69 SM
As explained on the previous page, there are several types of color shift problem. The following table shows the symptoms,
factors, action required, and the page to see for details.
Symptom Factors Action Required Refer to #
1 Color shift on entire image in
main-scan and/or sub-scan
directions
• Line
position
adjustment does not
function
properly.
•
Transfer
belt unit has just been
replaced.
• Check the result of the line position
adjustment
(SP5-993-007) and solve the
problem if an error was detected.
• Check which color lines are shifted from
black line and adjust the SP modes for
registration and magnification.
Page 4-4
Main-scan
Page 4-56/57
Sub-scan
Page 4-54/55
Transfer Unit
Page 4-60
2 Color shifts only at the
leading edge area
(sometimes causing shock
jitter, magenta or cyan lines) Registration roller speed is not
appropriate. Adjust the color development motor speed
(SP1-004-4, 5, and SP1-005-003) depending
on the process speed. Page 4-54
3 Color shifts only at the trailing
edge area Fusing belt/roller speed is not
appropriate. Adjust the black development motor speed
(SP1-004-001, 002, and 007, or “Fuser
Adjust” in the User Program mode) depending
on the process speed. Page 4-54
4
Color shifts between the front
and rear sides
Paper skew on transfer belt
•
Side fences are not properly set.
• Pressure between the paper
attraction roller and transfer belt is
not even at the front and rear
sides.
Reposition the side fences.
Reposition the paper attraction roller unit. Page 4-57