Dealing with a Keyboard Lockup
What to try first when your system ignores your keyboard:
- Assuming you’ve enabled Ctrl-Alt-Backspace, try that. If all goes wll it will log you out and let yo re-login.
- You can also try Ctrl+Alt+F1 which opens a virtual console.Then restart X Server from that virtual console under Ubuntu 12.04/11.10, with the following command:
sudo service lightdm restart
For Ubuntu 11.04 or older, use this command:
sudo service gdm restart
If all goes well, your desktop will disappear for a few moments and it will reload back.
Unfortunately if your X Server is frozen neither of these will work. In that case, use the sledgehammer approach–the SysRq key. The SysRq key is the same key would you use for print screen. With it you can take control away from the X Server, using the following key combination:
Then, you should be able to use Ctrl+Alt+F1 to access a virtual console and continue to restart the X Server as in case 2 above.