Heavy Color Registration Error; Display Of The Message "Color Adjustment Is In Progress" Appears Only Short Time; Though Reg Adjust Test Of Engine Maintenance Function Is Ok, Color Blur Occurs; Entirely Black Print - Oki MC760 Maintenance Manual

Oki Data CONFIDENTIAL

7.5.5.(6) Heavy color registration error

(6-1) Display of the message "Color adjustment is in progress" appears only short time.

Check item
(6-1-1) Result of color registration error correction
Color registration Use the self-diagnostic mode and execute the
error correction REG ADJUST TEST. Check the result. Error
time (If a printer is is issued but is not displayed on the ON LINE
normal, it is approx. display.
40 seconds.)
(6-1-2) Toner
Remaining amount Check if the message "Prepare toner
of toner replacement." or "Replace the toner." appears or
not.
(6-1-3) Color registration error detection sensor
Sensor is dirty Is toner or paper dust attached to the sensor?
(6-1-4) Color registration error detection sensor shutter
Shutter operation is Check the shutter operation by the self-
faulty diagnostic mode

(6-2) Though REG ADJUST TEST of engine maintenance function is ok, color blur occurs

Check item
(6-2-1) Paper feed system
Paper feed system Check if any obstacle exists in the paper feeding
of the paper running path, that hampers smooth paper run.
path
45376001TH Rev.1
Action to be taken
Check work
at NG
Replace the
sensor that
causes the error.
Clean the sensor
to remove stain.
Replace the
shutter. Replace
the PU board.
Replace toner
cartridge with
new one.
Clean the sensor
to remove stain
Replace the
shutter or tune
the mechanism
Action to be taken
Check work
at NG
Remove the
obstacle

7.5.5.(7) Entirely black print

(7-1) All black print over entire page

Check item
(7-1-1) High voltage contacting condition
CH terminal Check that the terminal coming from the printer
body contacts with the high voltage terminal that
is located on the left side of the ID unit when
viewed from the top by visual inspection.
CH terminal Check that the high voltage terminal keeps the
normal contacting condition on the high voltage
board. Open the left cover and remove the high
voltage board. Then, check that the terminal
is not installed in the abnormal installation
condition.
ID unit terminal Check that the high voltage terminal of the ID
unit is contacting with the Contact Assembly
normally by visual inspection. (Refer to Figure
7-3.)
(7-1-2) High voltage output condition
CH output If high voltage probe is available as a
maintenance tool, open the left cover, and check
the CH output with the high voltage probe from
the soldering side of the high voltage board.
(The high voltage probe is not an ordinary
maintenance tool.)
7. Troubleshooting and repair procedure
Action to be taken
Check work
at NG
Replace the
terminal of
printer side.
Correct the
installation
condition of
the terminal
to the normal
condition.
Replace the ID
unit or replace
the high voltage
board or correct
the high voltage
terminal.
If any attempt
of using new ID
unit as a trial
is going to be
made, be sure to
use the System
Maintenance
Menu FUSE
KEEP MODE.
Replace the high
voltage board.
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