Vertical repetitive defects
The print cartridge might be damaged. If a repetitive mark
occurs at the same spot on the page, install a new
HP print cartridge. See
Replace the print cartridge
The internal parts might have toner on them. See
for more information. If the defects occur on
the back of the page, the problem will probably correct
itself after a few more printed pages.
In your printer driver, make sure the appropriate media
type is selected.