Same problem. Followed the procedure outlined by Brother, cleaned the platen glass, white pressure pad, and window for document feed, no luck, so went to the drum, it had a black band all the way around so cleaned it, Ran the little tab back and forth across the wires and still had the problem. Only had a bad copy when using document feeder, so cleaned the platen glass and document feeder glass again and then discovered a panel on bottom of document feeder, opened it and found 3 gray feed rollers on left side. One was at exactly the same distance from edge where the unwanted lines appear so I cleaned it alcohol and that seems to have corrected the problem.