Image Faults; Black Line Appearing In Sub Scanning Direction On Image Due To Fluff Adhered To The Leaser Exposure Path - Canon imageRUNNER ADVANCE 8500 series Troubleshooting Manual

Image Faults

Black Line appearing in sub scanning direction on image due to
fluff adhered to the leaser exposure path.
[Symptom]
Black line in sub scanning direction [a] may occur.
The arrow [b] indicates the direction of feeding.
[Cause]
If fluffy foreign matter is adhered to the leaser exposure path which is located between the Laser Scanner Unit and the Developing
Unit, the laser light is blocked and a latent image cannot be formed. As a result, the symptom occurs.
[Service work]
1) Remove the process unit by following the steps in Service Manual "Parts Replacement and Cleaning > Image Formation
System > Cleaning the Process Unit".
2) Remove the developing unit by following the steps in Service Manual "Parts Replacement and Cleaning > Image Formation
System > Removing the Developing Assembly".
3) Check to see if any fluffy foreign matter is attached to the developing sleeve [a] in the developing assembly and remove if
found.
If no fluffy foreign matter is attached, proceed to Step 4).
4) Remove the laser scanner unit by following the steps in Service Manual "Parts Replacement and Cleaning > Laser Exposure
System > Removing the Laser Scanner Unit".
5) Check to see if any fluffy foreign matter is attached to the area near [a] the laser scanner unit and remove if found.
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