I've been trying to configure my TV as external monitor, because the only thing I saw on it was a white background with a X as cursor.
I tried around in the nVidia XServer Settings, but I never got it working that it would disable the laptop monitor and move to my TV as soon as I'd plug in the HDMI cable. After not beeing able to get it to work, I tought I'd rename xorg.conf so it would create a default configuration again (at least I tought it would).
After a restart, I got the login screen. I entered my credentials, screen went black for a second, followed by a short sequence of the nvidia logo when it finally threw me back to the login screen. I tried logging in again, but same behaviour.
I quickly booted to the root shell, renamed the old file back to xorg.conf, but it still wouldn't work. I then tried booting into failsafe mode, which told me that he couldn't detect any screens. Bootet up again, went to tty3 console, and tried the following:
sudo service lightdm stop sudo Xorg -configure
This leads to
Number of created screems dpes mpt ,match number of detected devices.
ddxSigGiveUp: CLosing log
Server terminated with error (2). CLosing log file.
Also, I can only selected between
Ubuntu 2D at login, I tought there were some more options? I'm using default Ubuntu 12.04 Desktop.
If you need any log files, please let me know which ones so I can provide them.
Update: I tried this accepted answer. While using gdm I am able to login. As soon as I change it back to lightdm, I can't log in anymore. Any idea?