How do I reset the HP Photosmart 6520 when it stops working or won't print?

To reset the printer, turn it off and unplug the power cord, wait a minute, then plug the power cord back in and turn on the printer. You should also restart your computer as part of the troubleshooting process. HP recommends using only the power cord supplied by HP and connecting the printer directly to a wall outlet. (Page 3)