The Blank Display
When you step away from your Ubuntu computer for a few minutes, you will likely return to find the screen completely pitch black. This is because Ubuntu is configured to automatically suspend (or “blank”) the display after a short period of inactivity to conserve power and protect your monitor. While this is logical behavior for a laptop running on battery power, it is incredibly annoying if you are using a desktop PC, trying to read a long document without touching the mouse, or running a background process that you want to monitor from across the room.
How to Disable Screen Blanking via the GUI
The simplest way to stop your monitor from turning off is to adjust the system Power settings from the main Ubuntu settings menu.
1. Click the system menu in the top-right corner of your screen (where the network, volume, and power icons are).
2. Click on Settings.
3. In the left-hand sidebar, click on Power.
4. Look for the section labelled Power Saving Options.
5. Find the setting named Screen Blank (or “Blank Screen” depending on your exact version of GNOME).
6. Click the drop-down menu next to it. It is likely set to 5 minutes.
7. Scroll to the very bottom of the list and select Never.
Your screen will now remain fully illuminated permanently, regardless of how long the computer sits idle. You will have to manually turn off your physical monitor when you are finished using the computer.
How to Disable Screen Blanking via the Terminal
If you are setting up a kiosk, a dashboard display, or managing an Ubuntu machine remotely where you don’t have access to the graphical settings menu, you can disable screen blanking using the `gsettings` command.
1. Open your terminal application (Ctrl+Alt+T).
2. Run the following command to tell the GNOME desktop environment to set the idle delay to zero (which means ‘never turn off’):
gsettings set org.gnome.desktop.session idle-delay 0
3. (Optional) If you also want to ensure that the screen does not lock itself even if it stays on, run this command:
gsettings set org.gnome.desktop.screensaver lock-enabled false
These terminal commands take effect immediately. The system will no longer track your mouse or keyboard activity for the purpose of putting the display to sleep.