I had this problem with my old 2200. By the way, did you by chance have that ink run low or out on you when the problem occurred?
I made a very extensive search for potential solutions, and found that others had had the same problem, though not frequently by any means. I tried everything, to no avail. If you truly have the same problem I had, there is no easy fix.
Forget the diagnostic. It would just be wasted money. You are facing two choices: send it in for the flat-rate repair, or buy a new printer.
The price for the flat-rate repair is not terrible, actually. However, the 2200 is by now an ancient machine. If you can spare the money, you will want to consider a new printer, preferably an upgrade to a 3800. That was my choice, and WOW, what an improvement in every single respect! (Wait another week for PMA before choosing this option, just in case.)
Best of luck, and let us know how it turned out.