Open the front cover.

Note: You need to print the toner dot matrix checklist first (select “drum dot matrix printing” in the “Options” of the control panel), in order to understand the locations where the toner cartridge is not clean. Power off the device after printing

Remove the toner cartridge and drum unit assembly from the machine.

Press the green lock lever and remove the toner cartridge from the drum unit

Turn the drum unit to the other side. Make sure that the gear of the drum unit is on the left.

Locate the print on the print cartridge by the numbered mark next to the print cartridge roller. Example: If spots appear in column 2 of the checklist, it means there is a mark in the "2" print cartridge area.

When looking at the surface of the drum to find the mark, turn the edge of the drum unit toward you to look at the surface of the drum to find the mark.


1. To avoid print quality problems, do not touch the surface of the drum unit, only the edges.

2. You can pull down the black lever to make the drum unit gear easier to rotate. After completing the gear rotation, push the lever back to its original position.

Wipe the surface of the drum gently with a dry cotton swab until the mark is completely removed.

Note: Do not clean the surface of the photosensitive drum with a sharp object or any liquid.

Put the toner cartridge firmly into the drum unit until it locks into place and clicks.


1. Make sure that the toner cartridge is installed correctly, otherwise it may be offset from the drum unit.

2. When installed correctly, the green lock lever will automatically lift

Gently slide the green slider left and right several times to clean the corona wire inside the drum unit. Be sure to return the slider to the initial position. Otherwise, vertical streaks may appear on the printed pages.

Put the toner cartridge and drum unit assembly back in the machine. You have finished cleaning the printer drum unit and corona wire.