The Unexpected Darkness
Ubuntu, prioritizing power efficiency, incorporates aggressive screen management out of the box. By default, if you step away from your computer or simply read a long document without touching the mouse or keyboard for five minutes, the operating system will automatically blank the screen (suspend the display) to conserve energy. If you are rendering a video, running a complex terminal script, or monitoring a dashboard, this behavior is highly disruptive. It forces you to constantly wiggle the mouse to keep the monitor awake, and often requires you to re-enter your password to unlock the session once the screen has gone black.
Keeping the Display Active
To prioritize visibility over battery life and stop Ubuntu from automatically suspending the screen, you must adjust the system’s power and privacy timeouts.
Click the cluster of system icons in the top-right corner of your screen and select the gear icon to open the Settings app. First, navigate to the Power tab in the left-hand sidebar. Look for the “Power Saving Options” section on the right. Click the dropdown menu next to Screen Blank. Scroll to the very bottom of this list and explicitly select Never. This prevents the monitor from turning off. However, to ensure the system doesn’t still try to lock your session behind a password screen, you must also check the privacy settings. Go back to the left sidebar, select Privacy, and then click on Screen Lock. Ensure the Automatic Screen Lock toggle switch is turned Off. Your Ubuntu machine will now remain awake and unlocked indefinitely.