Brother 1250 Black and blurred horizontal stripes, Black vertical streaks in a gray background

CHAPTER 6 TROUBLESHOOTING

I-7

Black and blurred horizontal stripes

User Check

(1)The drum unit may be damaged. Install a new drum unit.

(2)Check the paper used meets the recommended paper specifications.

(3)Clean the printer interior and the corona wire in the drum unit.

Possible cause	Step	Check	Result	Remedy	Ground
					contacts
Scratch on the	1	Are the horizontal stripes at	Yes	The photosensitive
drum		94mm (photosensitive drum)		drum was scratched.
		intervals?		Replace the drum
				unit.
Toner stuck on	2	Are the horizontal stripes at	Yes	After printing several
the developer		39mm (developer roller)		pages, the problem
roller		intervals?		will disappear.
				If not, replace the
				toner cartridge.
Scratch on the	3	Are the horizontal stripes at	Yes	Replace the heat
heat roller		79mm (heat roller) intervals?		roller.
Corona contact	4	Are the charge electrodes	Yes	Clean both electrodes.	➂
failure		between the printer body and
		the drum unit dirty?
High-voltage	5	Is the problem solved after	Yes	Replace the high-
power supply		replacing the high-voltage		voltage power supply
PCB failure		power supply PCB?		PCB.

I-8

Black vertical streaks (in a gray background)

Possible cause	Step	Check	Result	Remedy	Ground
					contacts
Translucent	1	Is there any dirt on the scanner	Yes	1) Clean the scanner
stain on the		window?		window.
scanner window				2) If it is not effective,
				replace the laser
				unit.
Corona failure	2	Is the corona wire dirty?	Yes	Clean the corona wire	➁
				with the wire cleaner.

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