Canon LBP-1120 Service Manual page 88

CHAPTER 4
Susceptible location
Transfer charging roller
Fixing film unit
Pressure roller
Feed roller
Photosensitive drum
Developing cylinder
Primary charging roller
4 - 12
Table 4-2-2
Periodical dirt and spots appearing on the image
Diameter Period of the image
(mm)
(mm)
Approx. 45
14.4
Approx. 75
24
20 Approx. 63
Approx. 52
16.5
Approx. 75
24
12 Approx. 38
Approx. 38
12
Phenomenon
Dirt on back
Blank
Dirt
spots of paper
Poor fixing]