Brother HL-2400C Service Manual page 293

I-9 Black Line / Blur in the Image
Phenomenon
Fine black line or blur appears in the printed image as shown in
2.
Main Causes
1) The corona wire of the charger unit is dirty.
2) OPC belt surface is damaged.
3) Foreign particles (paper dust, etc.) are stuck between the cleaning blade and OPC
belt.
4) Debris adhering to the base of the toner cartridge's developer roller where it contacts
with the OPC belt.
Countermeasures
1) Remove the OPC belt cartridge.
1-1) Clean the charger unit (corona wire). (See
1-2) Replace the OPC belt cartridge with a new one. (See
2) Clean the surface of the developer roller.
I-10 Vertical Line
Phenomenon
Vertical line appears in the printed image as shown in
Main Causes
1) Foreign particles (dust, etc.) adhering to the parts located around the transfer drum,
and consequently in contact with the toner image on the transfer drum.
2) Damage of the OPC belt due to foreign particles adhering to the blade of the OPC
belt.
Countermeasures
1) Clean the paper discharger unit. (See
2) Clean the charger unit (corona wire) of the OPC belt cartridge. (See
Chapter VI.)
3) Clean the rear face of the waste toner feeder.
4) Replace the OPC belt cartridge with a new one.
Section 1.2.6 of Chapter
print sample (10) of
Section 1.2.5 of Chapter
VIII-48
print sample (9) of Fig.8-
VI.)
Section 2.1 of Chapter
Fig.8-2.
VI.)
Section 1.2.6 of
VI.)