My problem was the black and white and greyscale scanning and copying were working fine, but the color copying and scanning were very poor on the letters and there were lines vertically on the whole page and worse on color photos on the page. The method of unplugging from the back while turned on, waiting, and then replugging into the back worked, and the color copy and scanning are now fine.
same link as above http://h10025.www1.hp.com/ewfrf/wc/document?docname=c02881567&tmp_task=solveCategory&cc=us&dlc=en&lang=en&lc=en&product=4323659
P.S. I don't see where to mark as "accepted as solution."