How to Troubleshoot a Clean Corona Wire on Drum Error Message on a Brother 7820

1. Turn the unit off. Open the 7820's front cover. Pull the drum unit and cartridge assembly straight out, and set on a cloth or disposable paper.
2. Locate the blue tab on the top of the drum unit. Slide the blue tab from right to left several times. This cleans the corona wire inside the drum unit.
3. Move the blue tab back to its original position, marked by a triangle.
4. Replace the drum unit and toner cartridge assembly into the 7820. Close the front cover. Turn the unit back on.