I spent several hours today trying to troubleshoot the plotter for our facility. It's a nice 42" plotter -- great for the posters we need for a corporate event this weekend. Unfortunately, our media person got called away suddenly due to a personal crisis. So it ended up in my lap -- and I'd never printed to it. Worked great; but the pictures were cut off at 14" or so horizontally. Nice sharp demarcation between 1/3 of a great poster and 2/3 of a blank page. Every paper size in the book produced the same results. Reinstalled drivers, bypassed print servers, etc.
Lesson Learned: The basics of troubleshooting apply even for a $4000 printer with a 17 day uptime. Cycle power. Worked like a charm afterwards. And HP/google was absolutely no help.