Olivetti d-color MF651, Service Manual, Page: 939 / 1053

Field Service Ver. 2.0 Jul. 2009 22. IMAGE QUALITY PROBLEM
879
TROUBLESHOOTING
22.3.17 Printer monocolor: uneven density in sub scan direction
A. Typical faulty images
B. Troubleshooting procedure
A02EF4C520DA
Step Section Check item Result Action
1 High image
density original Uneven density in sub scan direc-
tion occurs at a pitch of 40 mm to
50 mm when a multi-copy cycle is
run using an original with high
image density (50% or more). YES Feed 10 to 20 blank sheets of
paper with no originals placed, as
the IU fails to keep up with a high
demand for toner.
2 Machine
o
LD adjust-
ment
o
LD
lightness bal-
ance adjust.
(Service Mode)
The problem has been eliminated
through the LD lightness balance
adjust. NO Go to next step.
3 Imaging unit The surface of the PC drum is
scratched. YES Change imaging unit.
4 Dirty on the outside. YES Clean.
5 PH unit The surface of the PH window is
dirty. YES Clean with cleaning jig.
6 Transfer belt
unit Is abnormality found in the cam
gear? YES Change transfer belt unit.
7 The problem has been eliminated
through the checks of steps up to 6. NO Change IU.
o Change PH unit.
o Change High voltage unit/2.
Y110571-1 Service Manual