Canon LASER CLASS 730i, Service Manual

Page: 117 / 436

LASER CLASS 730i/720i/710 Chapter 4: Maintenance and Service
4-34
• Light
Solutions:
(1) Remove the toner cartridge and shake it lightly five or six times.
(2) Verify that user data “COMMON SETTING” “DENSITY
CONTROL” is settings.
(3) Replace the toner cartridge.
(4) Open the printer cover during printing, and remove the toner
cartridge. Open the cartridge drum cover shutter manually, and
check whether the toner image on the photosensitive drum is
transferred onto the paper. If it is transferred, go to item (7). If not,
go the following step.
(5) Clean the transfer bias contact and the transfer charging roller shaft
contact.
(6) Replace the transfer charging roller.
(7) Clean the developing bias contact and the toner cartridge contact.
(8) Replace the EPU board.
(9) Replace the ECU board.
(10) Replace the LASER/scanner section.
(11) Replace the SCNT board.
(12) Replace the power supply unit.
• Dark
Solutions: (1) Verify that user data “COMMON SETTING” “DENSITY
CONTROL” is settings.
(2) Clean the drum ground contact and the toner cartridge contact
(3) Clean the primary charging contact and the toner cartridge contact.
(4) Replace the LASER/scanner section.
(5) Replace the SCNT board.
• Completely blank
Solutions: (1) Clean the developing bias contact and the toner cartridge contact.
(2) Check whether the projection for opening and closing the LASER
shutter on the toner cartridge is damaged.
(3) Replace the LASER shutter lever or the LASER shutter.
(4) Replace the ECU board.
(5) Replace the LASER/scanner section.
(6) Replace the SCNT board.
(7) Replace the power supply unit.
• All black
Solutions:
(1) Replace the toner cartridge.
(2) Clean the primary charging contact and the toner cartridge contact.
(3) Replace the ECU board.
(4) Replace the LASER/scanner section.
(5) Replace the SCNT board.
(6) Replace the power supply unit