Canon mf6600 Series Service Manual

66 6-46-4Trouble Shooting > Trouble Shooting Items > Image Defects > White SpotsTrouble Shooting > Trouble Shooting Items > Image Defects > White SpotsCompletely BlankNo image printsCause Solution1) The laser shutter open/close projection part ofthe cartridge is damagedReplace the cartridge.2) The laser shutter arm and laser shutter aremalfunctioning or damagedIf the laser shutter arm or laser shutter does notmove smoothly or if the part is damaged, replaceany defective parts.3) Poor developing bias contact with the cartridge Clean the contact if dirty.4) The high-voltage power supply is defective Replace the engine controller unit.All BlackImage is all blackCause Solution1) Poor primary charging bias contact with thecartridgeClean the contact if dirty.2) The primary charging roller is defective Replace the cartridge.3) The high-voltage power supply is defective Replace the engine controller unit.F-6-4F-6-4F-6-5F-6-5T-6-3T-6-3White SpotsWhite spots appear in imageCause Solution1) Poor contact exists to the static chargeeliminatorClean the contact if dirty.2) The transfer roller is deformed or hasdeterioratedReplace the transfer roller.3) Poor contact exists between the transfer rollerand its shaftClean the contact if dirty.4) The high-voltage power supply is defective Replace the engine controller unit.5) Scratches/stain on the Drum Replace the Cartridge.F-6-6F-6-6T-6-4T-6-4