My fresh installation (with updates ...) of ubuntu 12.04 (64bit, Desktop) automatically dims the virtual console as soon as a switch to one. After pressing ctrl+alt+fX, the screen starts dimming until it is completely black after 4-5 sec. Unlike normal power saving, the console stays black even after keystrokes (i can login) until i switch back to X. Back in X, the screen just "undims" until it has normal brightness.
It might be worth to point out that I don't even have a laptop but a standard desktop pc.
So what can I do ?
This is NO duplicate of How to permanently disable monitor power saver using the command line?. As I said, the virtual console is dimmed even if X is not running!