Canon imageRUNNER 2270 Service Manual page 565

14.2.1.1.2 Uneven Density Caused by Irregular Rotation of the Main Motor
<Symptom>
Uneven density at specific intervals tends to occur in sub scanning direction (from leading
edge to trailing edge in relation to paper movement) when the main motor starts to rotate
irregularly.
- iR2270/2870
intervals of about 3.5 mm
- iR3570/4570
intervals of about 6.3 mm
To facilitate a check, use a halftone test pattern.
<Remedy>
Replace the main motor.
14.2.1.2 Partially Blank/Streaked
14.2.1.2.1 White lines appear in sub scanning direction on solid black and
halftone images: Dust on top cover of Developing Assembly
[ Inspected by Canon Inc. ]
Description
As a result of inspection, it was found this symptom occurred because the laser light was
intercepted by dust on the top cover of the developing assembly. If the symptom occurs,
remove the developing assembly and clean its top cover referring to the Service Manual
[Maintenance and Inspection > Cleaning > Cleaning the Developing Assembly Spacer,
Feed Guide, Dust-Blocking Glass and Fixing Inlet Guide].
Chapter 14
0007-9967
0008-3408
14-7