I asked Ron if he'd tried turning it off and on and/or disconnecting the electric cord from the wall for 15 minutes. He humored me and said yes they had without sounding disdainful of the question! Really, it is important to ask this, so don't be offended...there are hundreds of problems that can be quickly and easily solved with just turning the darned thing off!!!
I told Ron to turn off the printer, take all the cartridges out. Turn the printer back on and make the printer ask for ink. It asked, he reinstalled the ink cartridges. That solved the problem. The printer came quickly to READY.