Canon iR3570 Series, Service Manual

Page: 540 / 722

Chapter 14
14-12
F-14-7
14.2.1.4.6 Horizontal Line/Blurring at Intervals of 94 to 95 mm
0007-7091
iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /
<Cause>
The coefficient of friction on the surface of the photosensitive drum where the edge of the cleaning blade remains in contact tends to change, causing uneven rotation
and thus blurring.
This problem tends to occur during the initial period of use (less than 10K), when the coefficient of friction is relatively even, or when a halftone image is generated
after leaving the machine alone for 1 to 2 days. This problem, on the other hand, tends to disappear when about 10 printouts are made.
This problem can also occur when the drum unit is taken out of and put back in the machine, with the edge of the cleaning blade forcing itself against the surface
of the photopositive drum and increasing the friction.
<Field Remedy>
Make about 10 copies of the Test Chart.
<Image Sample>
F-14-8
14.2.1.4.7 White Lines in Sub Scanning Direction
0007-7465
iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /
<Cause>
The presence of foreign matter inside the developing assembly can make its way to the developing cylinder, preventing toner from being evenly deposited on the
cylinder and, thus causing white lines.
<Field Remedy>
Replace the Developing Assembly
<Image Sample>