Smear On Back; Uneven Image Density; Gradation Reproduction Failure - Minolta Di450 Service Manual

(10) Smear on back

Section Step
1 Suction Belts are dirty.
2 Image Transfer Corona is dirty.
3 Image Transfer Guide Plate is
dirty.
Engine
4 Pre-Fusing Guide Plate is
dirty.
5 Fusing Rollers are dirty.
6 Toner spilled over area inside
copier.

(11) Uneven image density

Section Step
1 PC Drum is properly
grounded.
2 Comb Electrode and grid
mesh are dirty or deteriorated.
Engine
3 Image Transfer Corona is dirty
or deteriorated.
4 Toner is even on Sleeve/Mag-
net Roller.
1 Mirrors and lens are dirty.
IR
2 Exposure Lamp is dirty or
deteriorated.

(12) Gradation reproduction failure

Section Step
1 Wiring between PH Unit and
Engine Image Processing Board is
connected.
1 Shading sheet is dirty.
2 Wiring between CCD Assy
IR and Image Processing Board
is connected.
Check Result
YES Clean.
YES Clean.
NO
YES Clean.
YES Clean or change.
YES Clean.
Check Result
NO
YES Clean or change.
YES Change.
NO
YES Clean.
YES Clean or change.
Check Result
YES Change PH Unit.
YES Clean.
YES Change CCD Assy.
NO
T-77
Action
Clean.
Action
Clean or change PC Drum
ground plate.
Adjust DB. (See ADJUST-
MENT.) Correct developer
conveying mechanism.
Action
Change Image Processing
Board.
Change Image Processing
Board.
Connect.