CHAPTER 4 TROUBLESHOOTING IMAGE FAULTS/MALFUNCTIONS
4-12
3.4 The copy has uneven density (darker at front).
3.5 The copy has uneven density (lighter at front).
Developing assembly
1) Are the developing block members of the developing assembly in firm
contact with the developing assembly?
NO:
Check the developing assembly locking unit.
Scanner
2) Clean the scanning lamp, reflecting plate, mirrors, and lenses. Is the
problem corrected?
YES: End.
Pre-exposure lamp
3) Is the pre-exposure lamp ON during copying operation?
NO:
1.
Replace the pre-exposure lamp unit.
2.
Replace the DC controller PCB.
Developing assembly
4) Is the coating of toner on the developing cylinder even?
NO:
1.
Clean the tip of the blade of the developing assembly. (dry wiping)
2.
Clean the surface of the developing cylinder.
3.
Check the toner inside the developing assembly for uneven deposit.
5) Try the following modes. Is the problem corrected?
•
APVC adjustment once gain in service mode: FUNCTION>DPC>D-
GAMMA.
•
ATVC adjustment once again in user mode: ‘roller clean’ under ‘adjust/
clean’.
YES: End.
Drum cartridge, Shading
6) Is there an uneven image in the halftone area of PG?
YES: Replace the drum unit.
NO:
Execute shading adjustment (i.e., FUNCTION>CCD>CCD-ADJ).
