Ubuntu – Disable automatic screen dimming


I currently have three computers running Ubuntu. With two of them, If I don't touch the mouse or keyboard… nothing happens. However, with the third, the screen gets dimmer after about 60 seconds of inactivity. I can't seem to figure out how to prevent this.

I've tried using the control center (gnome-control-center –overview), entering the "Brightness and Lock" screen, and unchecking the "Dim screen to save power" checkbox, but that doesn't actually seem to have any effect on the issue.

I'm running 32-bit Ubuntu 13.04, with the Cinnamon desktop. I also used to have KDE-Plasma, although I decided to get rid of it. Any Ideas?

Best Answer

I seem to have found the cause of the problem, as well as the solution; apparently,there was some strange power management package installed.

I noticed a few weeks ago that the hard drive was powering down after three or four seconds (literally) of inactivity. So, after attempting to remedy the hard drive issue using the software from THIS page, I get a message telling me that tlp can't start because of a package called laptop-mode-tools, as well as a recommendation to remove it.

So, I powered up another Ubuntu laptop, which hasn't given me any real problems, and checked to see if it had that same package (using sudo apt-get purge laptop-mode-tools -s), and found that said package didn't exist, which made me assume it probably isn't particularly necessary. After removing both packages (that is, tlp and laptop-mode-tools), and rebooting the system, the both hard drive spin-down, and the dimming screen issues were solved.