Brother HL-1040, HL-820 Black and blurred vertical streaks, Black and blurred horizontal stripes

I-6

Black and blurred vertical streaks

Possible cause	Step	Check	Result	Remedy	HV.GND
					contacts
					(Fig.4-5)
Corona failure	1	Is the corona wire dirty?	Yes	Clean the corona
				wire with the wire	➇
				cleaner.
Corona failure	2	Is the vertical block streak	Yes	Return the wire
		about 10mm wide?		cleaner to its home
		Is the corona wire cleaner not		position.
		in its home position?
Dirt in the paper	3	Is the paper tray or feed	Yes	Clean the toner off.
feed system		system on the drum unit soiled
		with toner?
Scratch on the	4	Is the drum surface scratched?	Yes	Replace the drum
drum				unit.
Cleaning failure	5	Is the drum surface dirty with	Yes	Replace the drum
		toner in streaks?		unit.
Scratch on the	6	Is the surface of the heat roller	Yes	Replace the fixing
heat roller		scratched?		unit.

Note:

If you print the same pattern continuously, the drum will be worn and black vertical streaks will appear on the paper.

I-7

Black and blurred horizontal stripes

Possible cause	Step	Check	Result	Remedy
Scratch on the	1	Are the horizontal stripes at	Yes	Replace the drum unit.
drum		94mm (OPC drum) intervals?
Toner stuck on	2	Are the horizontal stripes at	Yes	Print several sheet and see
the developer		25mm (developer roller)		what happens.
roller		intervals?		The problem will disappear
				after a while. If not, replace the
				drum unit.
Scratch on the	3	Are the horizontal streaks at	Yes	Replace the fixing unit.
fixing roller		63mm (heat roller) intervals?
High-voltage	4	Is the problem solved after the	Yes	Replace the high-voltage
power supply		high-voltage power supply		power supply PCB.
PCB		PCB is replaced?

IV-10