Canon GP335, Руководство по обслуживанию, Страница: 143 / 200

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CHAPTER 4 SERVICE MODE
1. Grid Test Print
Use it to check the angles (right angles)
and lines (straight lines).
• If the lines are not straight,
• suspect a displaced laser beam or a
BD fault.
2. 17-Gradation Test Print (with density
correction)
3. 17-Gradation Test print (without density
correction)
Use it to check gradation, fogging, white
lines, and uneven density between left and
right.
• If the gradation is poor, suspect a fault
in the laser system.
• If fogging is noted, suspect a fault in
the photosensitive drum, developing
system, or laser.
• If white lines (bands) are noted,
suspect a fault in the developing
system or dirt on the transfer charging
roller.
• If white lines are noted, suspect
shading faults caused by dirt on the
standard white plate.
• If uneven density between left and
right is noted, suspect dirt on the
primary charging roller or the
developing assembly.
No.1
No.2
No.3