Oki C911 Maintenance Manual page 26

Oki Data CONFIDENTIAL
Outline of color registration correction
The color registration is corrected by reading registration patterns that are printed on the belt
with the color registration sensors located inside the sensor shutter under the belt unit. These
sensors are used to detect and to regist with the color registration patterns.
Automatic start timing of color registration
<Full Adjust>
• Power-on / closing the front cover at the replacement of consumables
• When changing the color registration setting from MANUAL to AUTO.
<Fine Only>
• Power-on
• Closing the front cover
• When printing 400 pages or more from the previous execution
• When starting to print after leaving for six hours or more
A registration error may be issued due to an inadequate toner amount of the registration
pattern printed, a sensor being soiled with toner, failure of opening / closing of the shutter, or
for other reasons. However, even if an error is issued, it is not indicated on the operator panel.
Therefore, implemented color registration correction will have to be performed in the self-
diagnostic mode (section 5.3.2.6) to check the error indication.
45530603TH Rev.2
Error checking methods and countermeasure
The color registration test function among the other self-diagnostic functions is applied to
check errors. (Section 5.3.2.6)
Countermeasure for each errors
• DYNAMICRANGE (L or R)
Check 1: If the above indication appears, check the connected state of the sensor
cable.
If the connected state is found abnormal, restore it to the normal state.
Check 2: Check whether the sensor surface is soiled with toner, paper dust or any
other foreign matter.
If it is found soiled, wipe it clean.
Check 3: Check whether the sensor shutter opens and closes normally from to use
by the MOTOR & CLUTCH TEST of the self-diagnostic function. If the
shutter operates imperfectly, replace the shutter unit.
If no problem was found by the checks 1 through 3, there is a problem with the circuit.
Replace each of the sensor PCBs, the PU board (F1Y PCB) and the connection
cable one by one and check that no error will occur again.
• (S1 or S2 or S3 or S4) LEFT, (S1 or S2 or S3 or S4) RIGHT, (S1 or S2 or S3 or S4)
HORIZONTAL
Check 4: If the above indication appears, check whether the toner is running short,
based on an NG-issuing color.
Replace the toner cartridge as needed.
2. DESCRIPTION OF OPERATION
2-11