My ubuntu 13.04 doesn't boot anymore. Eternal black screen. If I press ALT+CTRL+F1 I see that it's stucked on "Checking battery state [OK]." I'd like to try to go with

sudo apt-get install gdm

but I can't login on terminal tty2, tty3 etc. They correctly ask for my nickname, then they make me wait a lot, ask for password and make me wait again. After a lot of time (... a lot) the best I could achieve was visualizing "Documentantion https://help.ubuntu.com". I can never reach the point where I can give commands. Plus, during the long pauses, every 2 minutes it gives a messagge like this:

INFO: task XXX blocked for more than 120 seconds.

Any suggestion? Sorry for my bad english and thanks everyone for the attention.