These types of lines are typically caused by dirt or white out (correction fluid) on the scanner unit, or the corona wire for printing is dirty. This problem is usually resolved by cleaning the scanner glass, scanner glass strip and white plastic bar with a soft lint-free cloth, or cleaning the corona wire.
Please refer to the following instructions to clear vertical lines or streaks:
We recommend unplugging the power cord for safety.
If you continue to experience vertical lines, repeat the cleaning process. If the problem continues after multiple cleanings, please contact Brother Customer Service from "Contact Us".