Brother International HL-2400C Service Manual - Page 301

I-25 Vertical Smear Phenomenon Printed image is smeared vertically as shown in print sample (25) of Fig.8-2. Main Causes 1) Paper dust between the cleaning blade and OPC belt. 2) Debris adhering to the base of a toner cartridge's developer roller where it contacts with the OPC belt. Countermeasures 1) Remove paper dust between the cleaning blade and OPC belt referring to the figure below. OPC Belt Cartridge Fig.8-10 2) Replace the OPC belt cartridge with a new one. I-26 Black Toner Light Phenomenon Black color of printed image is light as shown in print sample (26) of Fig.8-2, and the printer clatters at the same time. Main Causes Black toner in the cartridge has solidified because the printer is used under high temperature circumstance or due to continuous printing. Countermeasures Replace the black toner cartridge with a new one. VIII-56