Canon imageRUNNER ADVANCE C3330 Series Service Manual page 418

■ Full color 16-gradations (TYPE=14)
This test print is for mainly checking the gray balance, gradations of YMCBk singe color and fogging.
Check item
Gradation Check that 64 gradations density is properly reproduced in each color. Failure of Drum Unit
Fogging Check that fogging appears on white image area only.
Gray balance Check that density is even in each color on gray scale area.
White
Check method
406
Light areas
White
Assumed cause
Failure of Laser Scanner Unit
Failure of Drum Unit
Failure of Laser Scanner Unit
Failure of Drum Unit
6. Troubleshooting