Brother International MFC 8890DW Service Manual - Page 125

■ White vertical streaks - Clean the scanner windows of the laser unit with a soft lint-free cloth. (Refer to Fig. 3-6.) - Replace the toner cartridge with a new one. - Check the machine's environment. High temperature and high humidity conditions can cause this problem. - Damp (wet) paper might be used. Try to change to freshly unpacked paper. - Check if there is no dust in the gap between the toner cartridge and drum frame. Step 1 2 3 Cause Condensation Transfer failure Scanner windows of laser unit failure Check Has condensation occurred inside the machine? Is the transfer roller scratched? Is the problem solved after replacing the laser unit? Result Remedy Try to print several pages Yes or leave the machine 2 hours to allow it to reach room temperature. Yes Replace the drum unit. Replace the laser unit. Yes ■ White horizontal streaks - Check that the appropriate media type is selected in the printer driver. - The problem may disappear by itself. Try printing multiple pages to clear this problem especially if the machine has not been used for a long time. - The drum unit may be damaged. Replace the drum unit with a new one. Step 1 2 Cause Check Toner cartridge Are the electrodes on electrode contact the toner cartridge and failure machine body dirty? Drum unit Are the electrodes on electrode contact the drum unit and failure machine body dirty? Result Remedy Clean both electrodes. Yes (Refer to Fig. 3-2, Fig. 3-3.) Clean both electrodes. Yes (Refer to Fig. 3-2, Fig. 3-3.) 3-53 Confidential