
Slide the toner cartridge and drum unit assembly into the machine.
If it is not, printed pages may have a vertical stripe. Note: Make sure to return the green tab to the home position (arrow icon.) The arrow on the tab must be aligned with the arrow on the drum unit. Clean the corona wire inside the drum unit by gently sliding the green tab from left to right and right to left a few times.Take out the toner cartridge and drum unit assembly for the color shown on the machine's display.
Open the top cover until it locks in the open position. Make sure that the printer is powered on. With the printer powered on, you would open the printer's top cover, then you can take out the toner cartridge and drum unit assembly (for each color toner cartridge / drum assembly.) Then you can see the green tab on the drum unit, then slide the green tab back and forth.