Olivetti d-color MF651, Service Manual, Page: 940 / 1053

22. IMAGE QUALITY PROBLEM Field Service Ver. 2.0 Jul. 2009
880
TROUBLESHOOTING
22.3.18 Printer monocolor: uneven density in main scan direction
A. Typical faulty images
B. Troubleshooting procedure
A02EF4C521DA
Step Section Check item Result Action
1 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.
2 Imaging unit The surface of the PC drum is
scratched. YES Change imaging unit.
3 Dirty on the outside. YES Clean.
4 PH unit The surface of the PH window is
dirty. YES Clean with cleaning jig.
5 Transfer roller Check that the spring does not
come off during the pressure oper-
ation of the transfer roller. NO Correct.
Change transfer roller unit.
6 Transfer belt unit Transfer belt unit makes positive
contact with plates on rails.
NO Check and correct contacts.
7 Is abnormality found in the cam
gear? YES Change image transfer belt unit.
8 The problem has been eliminated
through the checks of steps up to 7. NO Change imaging unit.
o Change PH unit.
o
Change high voltage unit/2.
Service Manual Y110571-1