Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
Lets try the following.. remove all paper from the machine.
now, remove all ink tanks from the machine.. Then, leave the scanner cover raised, and with the ink tanks removed.
Unplug the machine from power, then press and hold the power button for 20 seconds. Then plug it back in. When you plug it back in watch the carriage that moves left to right. When it moves, do you see any paper or debris jammed under or around the carriage? If so, remove it. if not, then insert the ink tanks and see if the jammed message is now gone.
Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.