Print head on Canon IP4200 stuck on right-hand side?

Attempting to print something on my Canon IP4200 I got an error message "Service error 5110". Inspection of the printer reveals that the print haed is firmly stuck at the extreme right of its travel. There is no jammed paper and nothing else that might be obstructing it. What can I do?
Tony Brookes, January 2019


done
https://support.usa.canon.com/kb/index?page=content&id=ART152961

asdf, January 2019
link Click here to see other fixes for Canon.