Solution
This section describes what you should do if the vertical black streaks appear on the output.
Is the correct type of paper loaded in the machine?
Make sure you load paper that meets the requirements for use.
Are the feeder roller, and the scanning area clean?
Clean the feeder roller, and the scanning area.
Is the fixing unit clean?
Are the toner cartridges installed properly?
Make sure that the toner cartridges are properly installed.