Canon imageRUNNER ADVANCE C5255 Series Service Manual page 547

■ The 35-mm uneven image density due to the periodic deflection
of the developing cylinder
[Occurrence area]
Developing cylinder
[Cause]
In case that the durable advanced Developing Assembly is used under the high temperature
and high humidity environment, the slight periodic deflection on the developing cylinder may
occur. As a result, since the gap between the developing cylinder and the drum becomes
uneven, the uneven image density in a cycle of 35 mm due to a developing failure may occur.
[Occurrence condition]
In case that the durable advanced Developing Assembly is used under the high temperature
and high humidity environment.
This phenomenon tends to occur, when a solid image or a halftone image is copied.
[Remedy]
Adjustment of the maximum developing AC bias value (COPIER > OPTION > IMG-DEV >
ADJ-VPP) <Level 2> The applicable service mode setting value is set to "-1", and turn OFF
and then ON the main power. If a defect is not improved, check the images with lowering the
setting value one step by one step.
6
Troubleshooting > Troubleshooting items > Image Faults > Uneven Image Density at 94 mm of Paper Leading Edge
About 35mm
F-6-9
6 Troubleshooting > Troubleshooting items > Image Faults > Uneven Image Density at 94 mm of Paper Leading Edge
■ Uneven Image Density at 94 mm of Paper Leading Edge
[Occurrence area]
Fixing Unit
[Cause]
Usually, the paper, which passed the Fixing Unit, is fed to the Inner Delivery Roller along with
the separation guide. However, when thin paper is used, since the elasticity of the paper is
low, there is a possibility that the paper may be pulled by the roller if the paper leading edge
reaches the Inner Delivery Roller.
As a result, since the paper, which met the separation guide, comes floating, the nip angle of
the Fixing Unit changes.
For this reason, a density change may occur at around 94 mm from the image leading edge.
[Occurrence condition]
In case that the solid image is copied on the thin paper under the high temperature and high
humidity environment
[Remedy]
Please perform the following steps.
● In case that the Paper Setting for the Poor Image is "Thin Paper"
Setting of the ITOP temperature in thin paper (COPIER > OPTION > IMG-TR > FXS-TMP5)
<Level1>
Set the setting value of the applicable service mode to "-1", and turn OFF and then ON the
main power. If not improved, set the setting value to "-2."
6-9
About 95mm
F-6-10
6-9