Brother International MFC 8890DW Service Manual - Page 123

■ Dirt on the back of paper - This problem may disappear after printing approximately 10 pages of completely blank sheets. Step 1 2 Cause Check Result Remedy Scratch and Dirt Is the pressure roller Yes Print approximate 10 pages. on the fuser unit ASSY dirty? Is any other area in the machine dirty? No Replace the fuser unit. Scratch and Dirt Is the paper feed system Wipe dirt off. in the paper feed dirty? Yes system ■ Vertical streaks - This problem may occur with noise which is caused by dirt on the corona wire in the drum unit. In this case, clean the corona wire with the wire cleaner. - Replace the drum unit with a new one. - Replace the toner cartridge with a new one. Step 1 2 3 Cause Check Result Remedy Scratch and Dirt Is the paper feed system Wipe dirt off. in the paper feed dirty? Yes system Scratch and Dirt Are there scratch and Replace the drum unit. on the exposure dirt on the surface of the Yes drum exposure drum? Scratch and Dirt Are there scratch and Replace the fuser unit. on the heat roller dirt on the surface of the Yes heat roller? CAUTION : • If the machine prints the same pattern, especially including vertical streaks, continuously, black vertical streaks may appear on the paper since the electrostatic performance of the exposure drum is decreased temporally. ■ Black vertical streaks in a light background - Clean the inside of the machine and the corona wire in the drum unit. - Replace the toner cartridge with a new one. Step 1 Cause Drum unit failure Check Is the problem solved after replacing the drum unit? Result Remedy Yes Replace the drum unit. 3-51 Confidential