Brother International DCP 8040 Service Manual - Page 243

CHAPTER 6 TROUBLESHOOTING I-6 Black and blurred vertical streaks User Check (1) Clean the corona wire in the drum unit. (2) Check that the corona wire cleaner is at the home position. (3) Check that the toner cartridge is not empty. (4) The drum unit may be damaged. Install a new drum unit. (5) The toner cartridge may be damaged. Install a new toner cartridge. Possible cause Dirt on the scanner glass. Dirt on the CCD. Corona failure Dirt in the paper feed system Scratch on the drum Cleaning failure Scratch on the heat roller Step 1 2 3 4 5 6 7 Check Is there any dirt on that? Is there any dirt on that? Is the vertical block streak about 10mm wide? (Check if the wire cleaner is at its home position.) Is the paper tray or feed system on the drum unit dirty with toner? Is the drum surface scratched? Is the drum surface dirty with toner in streaks? Is the surface of the heat roller scratched? Result Yes Yes Yes Yes Yes Yes Yes Remedy Clean the scanner glass. Replace the CCD. Return the wire cleaner to its home position. Clean the toner off. Replace the drum unit. Replace the drum unit. Replace the fixing unit. NOTE: • If you print the same pattern (especially vertical streaks) continuously, electrostatic charge performance of the drum will decrease temporarily and black vertical streaks may appear on the paper. • This problem may occur with noise due to the corona wire being dirty. In that case, clean the corona wire with the wire cleaner. 6-40