07-29-2019 12:40 PM
If you are unable to manually move the print carriage so that you can remove the ink, your PIXMA MX870 would require service.
You are eligible for Canon's Upgrade Program. This is for out of warranty units which have been diagnosed to require service, or for some reason are incompatible with a new or upgraded system. This option allows you a one-time opportunity to purchase a replacement product, discounted from the list price.
To help you get up and running quickly, we also offer free standard shipping (if the order is completed by 12:30PM ET). If you would like to take part in this option, please call our Sales Department at (866) 443-8002 seven days a week, 8am to Midnight. Let them know you have been working with technical support and the Canon Upgrade Program was offered.
07-29-2019 01:31 PM
I accept the solution from Patrick, the Canon Expert, and will inquire into the Canon Upgrade Program.
Also, my printer is an MX860, not 870; I mistyped.
In addition, my wife fiwed it by sticking a thin spatula into the printer casing and pressing on the tops of the cartridges. This caused the problem cartridge to seat itself and the error went away.
BTW, I have never had a problem with this printer in its long lifetime. Go Canon!