44015503TH  Rev. 1 
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Oki  Data  CONFIDENTIAL
7.  TROUBLESHOOTING PROCEDURE
7.5.3.(6)  Heavy color registration error
(6-1)  Display of the message "Color adjustment is in progress" appears only short time.
Check item Check work
Action to be taken 
at NG
(6-1-1) Result of color registration error correction
Color registration 
error correction 
time (If a printer is 
normal, it is approx. 
40 seconds.)
 Use the self-diagnostic mode and e
xecute the 
REG ADJUST TEST. Check the result. Error 
is issued but is not displayed on the ON LINE 
display.
Replace the 
sensor that 
causes the 
error. Clean 
the sensor to 
remove stain. 
Replace the 
shutter. Replace 
the PU board.
(6-1-2) Toner
Remaining amount 
of toner
Check if the message “Prepare toner 
replacement.” or “Replace the toner.” appears or 
not
 Replace toner 
cartridge with 
new one.
(6-1-3) Color registration error detection sensor
Sensor is dirty  
  Is toner or paper dust attached to the sensor?  Clean the 
sensor to 
remove stain
(6-1-4) Color registration error detection sensor shutter
Shutter operation is 
faulty
Check the shutter operation by the self-
diagnostic mode
Replace the 
shutter or tune 
the mechanism
(6-2)  Though REG ADJUST TEST of engine maintenance function is ok, color blur 
occurs
Check item Check work
Action to be taken 
at NG
(6-2-1) Paper feed system
Paper feed system 
of the paper running 
path
Check if any obstacle exists in the paper feeding 
path, that hampers smooth paper run.
Remove the 
obstacle
7.5.3.(7)  Entirely black print
(7-1)  All black print over entire page
Check item Check work
Action to be taken 
at NG
(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.
 Replace the 
terminal of 
printer side.
 CH ter
minal 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.
Correct the 
installation 
condition of 
the terminal 
to the normal 
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.)
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.
(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.)
Replace the 
high voltage 
board.