Hi, I would try turning it on with the paper feed open and see if it starts up with a different error code to close the feed door or drawer. Maybe this will get you into the firmware update.
I would also double check there isn't a pesky tiny piece of paper torn from a previous paper jam. You can do so by getting a piece of card stock, trim it to maybe 2-3" x however long you need it and floss the printer along the route the paper is fed through from one side to the other. Sometimes the sensors are really picking something up. Be gentle with it. Make the clamp is loose, if there is one. But I've found little scraps. The worst was a copier that had a piece of paper crumpled between the motor assembly and the back of the machine. As you open the machine everything would be functioning fine, then when I'd close it all up I'd keep getting errors. It took months to find it and when I did it worked so much better!
