Broken system after update. Keyboard not working


I just updated my system after 15 holidays days without using it. The update process showed some warnings about nvidia-utils (sorry, didn’t copy then) and DID NOT complete normally. After power off, the sistem won’t boot and shows this screen. There’s nothing I can do there (the keyboard is not responding, altough the numlocks is on. Ctrl+D doesn’t work, password doesn’t work).

I read the note in the front page of the forum about nvidia drivers and broken systems, but afaik, it doesn’t point out to a solution.

My /home data is safe and backed up. Reinstalling is an acceptable solution for me. I just want to know if I can FIX my system instead of reinstalling it and learn something from it.