If nothing changed in your Ubuntu install (no updates, new software, etc.) when the printer stopped working, it's important to make sure it's not the printer that's at fault.
If you have access to another computer, test the printer with that to make sure it's not a printer problem. If you don't have that access, try booting to a Live CD of something, installing the printer drivers (if the printer isn't automatically sensed), and testing it that way.
Once you make sure the printer is healthy, if something did change with your install, try reversing the change(s), one at a time, and testing.
Last edited by frankbell; 01-16-2014 at 09:37 PM.