Brother International HL 1240 Service Manual - Page 139

CHAPTER 6 TROUBLESHOOTING I-6 Black and blurred vertical streaks PR99154 User Check (1) Clean the corona wire in the drum unit. (2) Check that the corona wire 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 Corona failure Dirt in the paper feed system Scratch on the drum Cleaning failure Scratch on the heat roller Step 1 2 3 Check Is the vertical block streak about 10mm wide? (Check if the wire cleaner is at its home position.) Is the paper cassette or feed system on the drum unit dirty with toner? Is the drum surface scratched? Result Yes Yes Yes Remedy Return the wire cleaner to its home position. Clean the toner off. Replace the drum unit. 4 Is the drum surface dirty with toner in streaks? Yes Replace the drum unit. 5 Is the surface of the heat roller Yes Replace the fixing unit. scratched? NOTE: If you print the same pattern continuously, the drum will be worn and black vertical streaks will appear on the paper. This problem may occur with noise due to the corona wire dirty. In that case, clean the corona wire with the wire cleaner. 6-29