Setting Your Screen Blank Timeout to Greater Than 15 Minutes
Open Terminal and run:
gsettings set org.gnome.desktop.session idle-delay 1800
This sets the blank screen delay to 30 minutes, or 1800 seconds. You can set any value in seconds. To use minutes directly without having to math it out in your head you can replace the “1800” with $((30*60)), replacing the “30” with however many minutes delay you’d like. For instance to use this method to set your screen blank timeout to 45 minutes…
gsettings set org.gnome.desktop.session idle-delay $((45*60))
After changing this in your terminal, the “screen blank” value in your “Settings → Power → Power Saving Options” will show “30 Minutes” (or whatever you set), even though there was not a 30 minutes option before.
To Set Screen Lock
The number of seconds after blank screen activation before locking the screen (The default is 0)
gsettings set org.gnome.desktop.screensaver lock-delay 0
For this to work you first need to set this to TRUE (default) to lock the screen when the blank screen goes active…
gsettings set org.gnome.desktop.screensaver lock-enabled true
