Mine started working a couple of times but I eventually gave up trying to fix it. A new print head was going to be about £50 (shop around if you go this route) with no guarantee that some other problem wouldn't need fixing too, and a professional re...
My MP600R did this to me today. I did not have any paper jam messages, just tried to print something and got the Print head is incorrect message. I took out all the inks, took out the print-head and reseated it - this made no difference. However...