Fluctuating Displacement In Any Color Of Ymc Occurs In The Vertical Scanning Direction - Canon imageRUNNER ADVANCE C5000 Series Technical Workbook

Symptom

Fluctuating displacement in any color of YMC occurs in the vertical scanning direction.

Description
Color displacement occurred in such a way that an amount of displacement in any color of Y/ M/ C fluctuated
in the vertical scanning direction.
The below shows the output image of PG31, [a] shows the paper feed direction, [1] to [5] show the number
of sheets, and [2] shows normal image.
Cause
Due to the failure in the encoder or the control PCB of the Drum Drive Assembly, the rotational speed of the
drum becomes unstable, resulting in color displacement.
[Reference] Color displacement may also occur because of changes in outside air temperature/ temperature
increase inside machine/ machine relocation.
Field Remedy
Assuming that the previous measure against mottled blank on image (thin ITB/ increased ITB tension/
decreased primary transfer roller pressure) has been already implemented and the system software has
been upgraded to Ver. 70.09 (DCON Ver. 66.05) or later, follow the steps below to clean the sensor or the
encoder of the Drum Drive Unit which causes color displacement, or replace the Drum Drive Unit
(FM1-B788-000).
1) Turn OFF the main power switch and open the front cover.
2) Remove the Upper Front Cover.
3) Remove the ITB Inner Cover. Turn the ITB Pressure Release Lever to the left to release the pressure.
4) Remove the Front Inner Handle Left Cover and the Front Inner Handle Right Cover, and open the
Process Unit Inner Cover.
5) Remove the Process Unit.
[Caution]
- Be sure not to touch the surface [A] of the photosensitive drum, otherwise failure may occur in the output
image.
pg. 140