Last update: 2012-8-21

The same problem (see below for the original article) occurred again in the second week of February 2012.  Seems to be triggered by a kernel header update.  (During mid-2012, there has been several months in which this problem did not occur so I originally thought this was fixed.  Sadly in August 2012 it occurred again.)

This time I used the following steps when it stuck at Checking Battery State:

Press Ctrl-Alt-F1 to bring up a terminal then login

sudo service lightdm stop
sudo service lightdm start

This will bring up the ubuntu desktop (but does not solve the problem on reboot), so I can do some web searches if necessary.  Please note that I use a Z68 chipset PC with on-board graphics.  Any other hardware configuration may very well be different in the steps required to fix similar problems.

I launched a terminal, then type:

dpkg --get-selections | grep nvidia

It only shows nvidia-common.  (It is very likely you will get different results if you use a hardware configuration different from mine.) I need to reinstall this, so I typed:

sudo apt-get remove --purge nvidia-common

It reported that nvidia-common is used by ubuntu-desktop which is also removed.  To get both reinstalled, I typed:

sudo apt-get install ubuntu-desktop

I made sure it also reinstalled nvidia-common.  After it finished, I shutdown the PC and restarted it to confirm it can boot properly.


Date: 2011-12-13

After Ubuntu 11.10 performed an automatic update, it refused to boot up, and was stuck at Checking Battery State.  After some google searches, I tried purging and reinstalling (sudo apt-get install) the following packages:

  • lightdm
  • ubuntu-desktop
  • lightdm-gtk-greeter
  • unity-greeter

It still did not work.  Installing gdm instead of lightdm would allow logging in, but the interface is different.  And some UI things seem strange.  Plus unity-3D would not work.

Some people solved the problem by reinstalling the nvidia driver.  However, I’m using a Z68 chipset system with on-board Intel graphics (i.e. I have no nVidia hardware), so I should not need to do it.  Strangely doing a “dpkg –get-selections | grep nvidia” would show “nvidia-common”.  So I tried reinstalling it, then the normal login screen can be shown.  (Some people say it is also necessary to “rm -f ~/.Xauthority”.)

At this point, logging in unity-3D would be abnormal (just show a menu on top), but unity (2D) worked.  Then I did the followings to recover the unity-3D:

  • rm -rf .config/compiz-1/
  • rm -rf .compiz*
  • rm -rf .gconf/apps/compiz*
  • rm -rf .cache/compizconfig-1/
  • unity –reset

Toke me 3 hours to solve this.