Open the scanner cover.
Using a damp, soft, lint‑free cloth, wipe the ADF glass and the white underside of the ADF cover.
Close the scanner cover.
Do vertical streaks still appear on scanned documents?
Go to step 2.
The problem is solved.
Open door C.
Close the door.
Contact customer support.
Check the paper settings in the print dialog and in the printer to get clean prints. Installing or replacing the imaging unit may also help solve this print quality issue.
Prevent vertical dark streaks with missing images on your prints by checking the toner cartridge.