The Blank Screen Issue
If you use Ubuntu for digital signage, a dashboard display, or even just reading long documents without touching the mouse, you have likely encountered the automatic display suspend feature. By default, Ubuntu’s desktop environments (like GNOME) and the underlying X11/Wayland display servers are configured to utilize DPMS (Display Power Management Signaling). After a set period of inactivity—usually around 5 to 10 minutes—the system will automatically signal your monitor to enter a low-power standby state, effectively blanking the screen to save energy and prevent burn-in.
Disabling DPMS via Xset
To keep your monitor active indefinitely and stop Ubuntu from automatically suspending the display due to inactivity, you must disable the power management signaling.
While you can adjust timeouts in the GNOME Settings GUI under “Power” or “Privacy,” these sometimes fail to override the low-level X server settings, especially on custom setups or older hardware. To definitively disable it in an X11 session, open a terminal window (Ctrl+Alt+T). You will use the `xset` utility. First, type xset s off and press Enter; this disables the traditional screen saver. Next, type xset -dpms and press Enter; this completely disables Display Power Management Signaling. Your screen will now stay on forever. Note that `xset` commands only persist for the current login session. To make this permanent, you must add these commands to your `.xprofile` file or a startup script that runs when you log in.