Canon Color iR C3480, Service Manual

Page: 494 / 774

Chapter 15
15-3
15.2.4 16-Gradation (TYPE=4)
0014-3135
Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080i / iR C2550
Use this test print to check gradation, fogging, white line, and uneven density at the front/rear.
- Gradation
If the 16-gradation[1] is not properly produced, suspect a fault in the drum unit or the laser exposure system.
- Fogging
If fogging is found only in the white area[2], suspect a fault in the drum unit or the laser exposure system.
- White Line
If a white line is found in the image, suspect a fault in the developing system.
- Uneven Density at the Front/Rear
If uneven density is found at the front/rear, suspect a fault in the drum unit, laser exposure system, or transfer system.
F-15-1
15.2.5 Full Page Halftone (TYPE=5)
0014-3136
Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080i / iR C2550
Use this test print to check a transfer fault, black line, white line, and uneven density at specific intervals.
MEMO:
- You can print out test prints for individual colors by making the following selections in service mode: COPIER>TEST>PG and then COLOR-Y/M/C/K.
- You can also change the density of the test prints by making the following selections in service mode: TEST>PG>DENS>Y/M/C/K.
(1) Transfer Fault
If a transfer fault (white spot) occurs, suspect a fault in the ITB unit or the secondary transfer outside roller.
(2) Black Line
If a black line occurs, suspect a scratch in the photosensitive drum or dirt on the primary charging roller.
(3) White Line
If a white line occurs, suspect a fault in the ITB unit, secondary transfer outside roller, or laser exposure system.
(4) Uneven Density
If the density is uneven at specific intervals, suspect the following:
(a) photosensitive drum (if at 94.2 mm)
(b) developing cylinder (if at 28mm)
(C) Charging roller(if at 42.7 mm)
(5) Uneven Density
If uneven density occurs, suspect dirt on the dust-blocking glass of the laser unit or deterioration of the ITB.
[1]
[2]