BROTHER MFC4800
Instrukcja Serwisowa

Trouble (5) Black and blurred vertical stripes or band

Action to be taken At the scanner Check the following components: - CIS unit At the printer side Clean the paper path which may be contaminated with toner. Slide the wire cleaner to clean the corona wire inside the drum unit. Make sure that the wire cleaner is returned to its home position. Replace the toner cartridge. Replace the drum unit. Replace the heat-fixing unit.

(6) Black vertical streaks on gray background

At the printer side Clean the laser beam window (glass) on the laser unit. Replace the laser unit.

(7) Black and blurred horizontal stripes

At the printer side Slide the wire cleaner to clean the corona wire inside the drum unit. If they appear at 94-mm or 17-mm intervals, replace the drum unit. If they appear at 54-mm intervals, replace the heat-fixing unit. Replace the high-voltage power supply PCB.

(8) Horizontal lines

At the printer side Check the connection between the right end of the paper feed roller and the grounding wire. (Contact in the illustration given on page 6-28.)

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