Yesterday morning I started getting a stripe of red ink, about 1/8th" wide, on my prints. I called Canon Tech Support and we did a head cleaning and a few test prints to confirm the problem. I only had 20 days left on my warranty and Canon replaced the head for free.
I did get a lecture on using non-Canon media, with the support guy saying head strikes and other problems like mine happen much more frequently, even with "good" third party papers. I stock 17 papers and none are by Canon. But I was pleased that even after being mildly chastised, there was no problem getting the head under warranty. This differs considerably with my experiences with Epson 9600 and 9800 printers, when Epson's telephone support wouldn't even consider helping me unless I could assure them that any problems I was experiencing were also present with Epson paper.
I'm curious if this is still Epson's policy. While I have nothing against Epson printers (except head clogging issues), Canon's excellent tech support has been greatly appreciated, if seldom needed for this printer or my iPF 8100 before it.
The head arrived this morning; I replaced it, ran a calibration print and am back in business, less than 24 hours after my call to tech support.