The surface of a drum is sensitive to light. Exposing the surface of a drum to strong light (especially direct sunlight) can permanently damage it.
Replace the photoconductor unit or its cleaning unit with the detached charger unit.
What You Need
Hex screwdriver
Newspaper or other paper
Time for Replacement
A message will appear when it nears the time to replace a component.
Print the counter list.
Press the [Counter] key and print out the counter list.
See Control Panel.
Replaceable Parts
PCU cleaning unit
Photoconductor unit