Probably reached it's print-count limit (aka, the "death timer"), easy fix though as you can reset the counter and it'll continue to work as normal, did this on my Epson C46 years back when it decided to say it needed a service (went over it's 8300 count limit) and refused to operate, but using a tool called "SSC Service Utility", I reset the counter and it worked fine like nothing had happened, may not be the issue you have, but it is likely... :)
It died recently though, tries to print, but something's gotten mangled inside so, it's junk now...