Hi,
I'm afraid it must be a sensor, as I opened the rear hatch and checked the rollers for minute pieces of paper; got out the "canned air" and made sure the printer's inner paper path was pristine, and still the wretched error message upon a restart.
Doubled checked that the ink cartridges...
:(My Pixma MP 760 recently needed new ink. I replaced two cartridges, did the basic service options, printed a number of pages successfully and shut it down.
When I next turned the printer on, I had an error message that stated" Rear Cover The paper is jammed. Clear the paper and press OK".
I...