Canon iR8500 Service Manual page 756

4 Blank (PG-TYPE4)
5 Halftone (PG-TYPE5)
I Halftone Processed by the Density Correction Block (image processing)
In addition to the level of performance of the image formation system, it also depends
on the density correction mechanism (e.g., AE).
6 Solid Black (PG-TYPE6)
COPYRIGHT© 2001 CANON INC.
F00-206-05
F00-206-06
F00-206-07
2000 2000 2000 2000 CANON iR8500/7200 REV.1 AUG. 2001
Fogging
faulty photosensitive drum
faulty developing system
faulty laser system
[1] Black Lines
scratches on drum
dirt on primary charging wire
[2] Vertical White Spots
faulty transfer
[3] Left/Right Uneven Density
faulty primary charging assembly
faulty developing system
[1] White Spots
faulty transfer
[2] White Lines
faulty shading
(dirt on standard white plate)
SERVICE MODE
COPIER>TEST
S-113