I have an Epson WF-4630 (all in one inkjet printer) that has started printing very precise vertical blue and yellow lines at very specific points on a page. The blue/yellow lines are about 1mm or less apart and about 2.5 -3 mm in length. The lines appear whether I copy a blank page or print a page though the width of the lines has varied occasionally. I have reset the machine; I have reloaded firmware with no material difference in outcome. In all other respects the pages print or copy...
Vertical Lines on Page
Vertical Lines on Page