On the desktop login screen (GDM3) my computer will put the screens into power saving mode after 15 seconds of inactivity. I would ideally like to disable power saving in this situation, or at least lengthen the period.

I have tried disabling all power saving options that I can find in gsettings, both for my user and for root, but this has not affected the 15 second timeout.

What else can I try?

I'm running Ubuntu 19.04 with Gnome Shell 3.32.2. I have found various older questions concerned with the same issue, but they all relate to LightDM:


4 Answers 4


This default setting (suspend at login) affects me in Pop!os 20.04. When away from home I want to login to my home PC, and it is set to boot at 6am. But that's no use when it suspends :)

This is an easy fix:

From: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=893964#22

It's 20 minutes, and is a result of the defaults in gnome-settings-daemon 3.28 changing to comply with European and American power-saving regulations.

there appears to be no way of switching the GDM suspend behaviour off

There's currently no UI for it, but if you append this to /etc/gdm3/greeter.dconf-defaults:

# Automatic suspend
# =================
# - Time inactive in seconds before suspending with AC power
#   1200=20 minutes, 0=never
# - What to do after sleep-inactive-ac-timeout
#   'blank', 'suspend', 'shutdown', 'hibernate', 'interactive' or 'nothing'
# - As above but when on battery
# sleep-inactive-battery-timeout=1200
# sleep-inactive-battery-type='suspend'

then reboot (or run "service gdm3 reload" as root), that should put the GDM session back to the pre-3.28 behaviour. The values are in seconds, with 0 meaning never; please adjust as needed.

Note: this still works in Ubuntu 21.10. Also, if you want the screens to go into suspend mode but you don't want to suspend, set a timeout, and set the type to be 'blank'

For changes to take effect, reboot or

sudo systemctl restart gdm3 

Create /etc/dconf/profile/gdm and add:


Create /etc/dconf/db/gdm.d/01-power and add:


Run sudo dconf update

  • Unfortunately, this does not appear to affect the monitor going into power saving mode after 15s. Sep 4, 2019 at 15:17
  • Even after a cold restart? Could not test it myself.
    – vanadium
    Sep 4, 2019 at 15:41
  • Yes. I think something else must be responsible for invoking the DPMS state. I'm wondering if it might be hard-coded. Sep 4, 2019 at 15:46
  • I am pretty sure this is configured through gsettings, I changed my answer: can you try that approach?
    – vanadium
    Sep 4, 2019 at 17:06

xset -dpms disables DPMS, meaning you will see a black screen, not an off monitor. xset +dpms re-enables it.

xset s 300 changes the timeout to 300 seconds.

Neither of these commands persist across logout, but you can add them to ~/.xsession.


Run the following script as root :


cat > /etc/lightdm/lightdm.conf.d/50-dpms.conf <<EOF
echo '[SeatDefaults]

cat > /usr/local/bin/dpms-stop <<EOF
sudo xhost +si:localuser:lightdm 
sudo su lightdm -s /bin/bash <<HERE
/usr/bin/xset -dpms

chmod +x /usr/local/bin/dpms-stop

Then reboot

  • Would you mind to explain what it does? Aug 30, 2019 at 14:43
  • Two files are created. One conf file for lightdm, which is calling a script called dpms-stop. So this script is created, what it does is to stop dpms (power management) when lightdm is launched.
    – jmary
    Aug 31, 2019 at 9:56
  • That's out of scope, OP uses GDM3, not lightdm, so this is not going to work.
    – mook765
    Sep 2, 2019 at 19:26

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