Trouble Shooting Items; Image Defects; Light Print; Dark Print - Canon mf6600 Series Service Manual

Trouble Shooting Items

Image Defects

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Light Print

F-6-2 F-6-2
Image is light in entire page
Cause
1) Print density is not adjusted properly
Open the cartridge door during a print operation and remove the cartridge. Open the photosensitive
drum shield of the cartridge to check the toner image on the drum surface. If the toner image is not
fully transferred to the media, go to step 2. If the toner on the photosensitive drum is faint, go to step
5. Do not open the drum shied for longer than 10 seconds.
2) The transfer roller is deformed or has
deteriorated
3) Poor contact exists between the transfer roller
and its shaft
4) The high-voltage power supply is defective
5) The laser scanner unit is defective
6
Trouble Shooting > Trouble Shooting Items > Image Defects > Dark Print
Solution
Adjust the print density by operating the external
device.
Replace the transfer roller.
Clean the contact if dirty.
Replace the engine controller unit.
Replace the laser scanner unit.
6 Trouble Shooting > Trouble Shooting Items > Image Defects > Dark Print
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Dark Print

F-6-3 F-6-3
Image is obviously dark
Cause
1) Print density is not adjusted properly
2) Poor drum grounding contact with the cartridge Clean a contact point of the Cartridge.
3) Poor primary charging bias contact with the
cartridge
4) The high-voltage power supply is defective
5) The laser scanner unit is defective
6) The high-voltage power supply is defective
T-6-1 T-6-1
Solution
Adjust the print density by operating the external
device.
Clean a contact point of the main body.
Replace the Cartridge.
Clean the contact if dirty.
Replace the engine controller unit.
Replace the laser scanner unit.
Replace the engine controller unit.
6-3
T-6-2 T-6-2
6-3