Lexmark CS963
Raise the scanner cover, and then remove the glass cleaner tool.
Wipe the ADF glass beside the scanner glass.
Open door A1, and then clean the ADF glass.
Return the tool to its place.
Close the scanner cover.
Note: For more information on cleaning the scanner, see Cleaning the scanner.
If the problem persists, then contact customer support.
Check the paper settings or load paper from a fresh package to stop seeing vertical dark lines on your prints.
Are your prints too dark? Try adjusting toner darkness or loading paper from a fresh package.