My 12.04 system hangs at "Checking battery state". At this stage, no commands work eg: ctrl+alt+f1, alt+f5. I ran recovery mode, I ran the command
sudo mount -o remount, rw sudo dpkg-reconfigure gdm
and gdm was the only one installed so I didn't get a GUI screen. I have an integrated graphics card "Intel Corporation Mobile 4 chipset Integrated Graphics Controller (rev 07)". So I cannot install nvidia drivers as everyone else suggests. I have gone through several similar questions but everyone suggests reconfiguring gdm or reinstalling graphic drivers.
sudo add-apt-repository ppa:ubuntu-x-swat/x-updates sudo apt-get update sudo apt-get upgrade
to get the latest x-swat drivers. The system still hung at the same line.
The other option is to reinstall ubuntu, which is out of the question, since we have a very specific install for our project where the settings are very hard to duplicate.