How can I turn off the autodim feature on my Linux laptop so it actually stays off?

Question

I have a vintage GD8000 laptop running Linux Mint 18.3, and I'm having trouble turning off the autodim feature.

I have turned off autodimming in Mint's preferences, and I have also turned it off in the GD8000's BIOS. However, the screen still dims after 90 seconds of input inactivity.

Is there a way I can turn off the autodim feature so it actually stays off?

--UPDATE--

I've observed a little more closely, and the screen is not precisely being dimmed, in the sense of backlighting remaining on but being at a lower intensity. The backlighting is turning off completely. (But the screen is still "painted" and can be partially seen in bright light.) I suspect this is not a Linux issue.

Answer 1

The answer will differ depending on what desktop environment you're using. Since you're on Linux Mint, I figured that it's pretty likely you're in a Desktop Environment that uses gsettings (like Gnome or Cinnamon).

There are a few options you can change on the command line:

• Try to set the brightness that the 'dim' function uses to full brightness (this might make your screen brighter when it dims)

  gsettings set org.gnome.settings-daemon.plugins.power idle-brightness 100

• Try to turn of auto-dimming altogether

  gsettings set org.gnome.settings-daemon.plugins.power idle-dim false

• Make the criteria for 'inactive' 0, meaning your screen never goes inactive.

  gsettings set org.gnome.desktop.session idle-delay 0

Any of the above options can also be changed graphically using dconf-editor

sudo apt-get install dconf-editor && dconf-editor