Brother HL-3450CN Service Manual page 312

I-1 Background
Phenomenon
Background is smeared due to toner spread as shown in
Main Causes
(1) Too small toner mass and charging level in the developing process.
(2) Poor contact of the developer roller's bias pole.
(3) Life expired or failure of the OPC belt cartridge.
(4) Failure of the high-voltage power supply unit.
Countermeasures
(1) Replace the toner cartridge.
(2) Confirm if the developer bias pole is deformed or not.
(3) Replace the OPC belt cartridge.
(4) Replace the high-voltage power supply unit.
I-2 Missing Image at Edge
Phenomenon
There is missing or peeling toner found in the image at the edge as shown in the
(2) of Page 8-45.
Main Causes
(1) Too small toner mass and charging level in the developing process.
(2) The OPC belt is deformed (waving).
Countermeasures
(1) Replace the toner cartridge with a new one.
(2) Replace the OPC belt cartridge with a new one.
print sample (1) of Page
8-49
HL-3450CN SERVICE MANUAL
8-45.
print sample