White streaks appear in the vertical direction

Cause
Solution
Reference

The LED head is dirty.

Wipe the LED head with soft tissue paper.

The toner is low."Toner Low. " or "Toner Empty. Replace with a new toner cartridge." is displayed, replace the toner cartridge.
The window film of the image drum is dirty.Wipe the window film with soft tissue paper.
The image drum has not been installed correctly.Please install the image drum correctly.
A foreign object is stuck in the image drum.Please replace the image drum.