Canon iR4570 Series Service Manual page 715

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-14-4
14.2.1.2.4 White Lines in Sub Scanning Direction
0007-7465
iR2270 / iR2870 / iR3570 / iR4570 / iR3530
<Cause>
The presence of foreign matter inside the developing assembly can make its way to the developing cylinder,