1-10
NO
YES
NO
YES
YES
NO
YES
NO
NO
YES
*Do not clean the grid plate.
YES
NO
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
[B]
[A]
Check the locked condition of the
developing assembly.
Check the value of DISPLAY>
DENS>DENS-Y, DENS-M, DENS-C,
DENS-K in service mode.
Is the density of
black normal?
Is the value of
DENS-K -20 or lower?
Compare the density of a test print
made of Bk halftone against one
made at time of installation or
replacement of the developer.
Is it more or less the same?
Is the surface of
the black toner concentration
sensor soiled?
Is the test print of Bk
mono halftone uneven?
Replace the Bk developer.
Check the supply of toner
from the hopper.
Go through the check
items for the developing
assembly.
Clean the surface of the
sensor.
Replace the
photosensitive drum and
developer (all colors).
Is the value of
DENS-Y, DENS-M,
DENS-C the specified
value ± 20?
Is it -20 or lower?
Remove the toner concentration
sensor from inside the developing
assembly.
Is the surface of
the sensor soiled?
Replace the developer.
Go through the check
items for the developing
assembly.
Check the supply of
toner from the hopper.
Replace the sensor.
Check Items for the Developing Assembly
1. Is the mechanism used to lock the developing assembly to
the photosensitive drum normal?
2. Is the position of the developing assembly normal?
3. Are the developing assembly butting roll and butting block
free of dirt?
4. Are the developing bias AC and DC outputs normal?
5. Is the developing cylinder coated with an even layer of toner?
Further, is the coating thick enough?
6. Is the position of the electrode of the developing cylinder
normal?
If a fault is found after making the above checks, perform
cleaning or adjustment as necessary.
If fogging or light density still occurs after making all above
checks (1 through 6), replace the developing assembly.
Correcting Fogging
Is fogging noted?
Is fogging noted
for all colors?
Is the primary charging
assembly soiled?
Execute FUNCTION>DPC>DPC
in service mode.
Is the value of
DISPLAY>DPOT>V00-500,
V00-700 normal>?
Check the developing assembly.
Is there a fault?
Replace the photosensitive drum and
developers (all colors).
To [D] of next page.
To [B].
Clean.*
Check the laser shutter,
and adjust the laser
power.
Reference (normal value):
V00-500: 430 to 570
V00-700: 600 to 800
Correct the fault.