Canon imageRUNNER ADVANCE C5255 Series Service Manual page 548

● In case that the Paper Setting for the Poor Image is "Plain Paper 1"
Setting of the ITOP temperature in the plain paper 1 (COPIER > OPTION > IMG-FIX > FX-S-
TMP) <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."
[Notes about remedy]
If the applicable service mode is changed and a heavy paper is fed, fixing capability may
deteriorate.
■ Missing color due to the laser exposure failure
[Occurrence area]
Developing Assembly
[Cause]
If pushing the drum unit to the Developing Assembly in installation, there is a possibility to
catch the Mylar sheet of the Developing Assembly downward.
As a result, since an optical path is shut when the laser for the applicable color is irradiated,
the image may become light.
[Occurrence condition]
The installation failure of the drum unit
6
Troubleshooting > Troubleshooting items > Image Faults > Missing color due to the laser exposure failure
F-6-11
6 Troubleshooting > Troubleshooting items > Image Faults > Missing color due to the laser exposure failure
[Remedy]
When installing the Drum Unit (Bk) to the host machine, perform the following procedures.
1) Pull out the Process Unit.
2) Remove a dummy Drum or Drum Unit.
3) Place the half fold paper on the Developing Assembly (Bk).
4) While the paper is set, install the Drum Unit (Bk) to the host machine.
6-10
Paper
F-6-12
Drum Unit (BK)
F-6-13
6-10