I have a triple monitor setup if it makes any difference.

When i lock my desktop it goes to sleep/shuts down monitors after a short time as expected.

My issue is that they keep waking up after this, and immediately goes to sleep again in what i believe may be around 20min cycles. When they wake up they do not display the lock screen, my main monitor outputs only a blue color for a few seconds and then back to sleep.

Since i have my desktop in my bedroom this creates an annoying blue light to regularly blast out over the room during the nights.

I assume some program is causing this, is there any logs of what and when it wakes up and from what?

  • Are you sure this isn't just a faulty monitor? I had a similar issue with my old monitor, only it woke up at random intervals. It was just a hardware fault.
    – raj
    Aug 28, 2020 at 13:44
  • Im pretty sure since i dual boot with Windows and dont have the same issue there. I also tried to recreate this issue and the blue colored screen seems to be my monitors "No HDMI Signal"-screen.
    – frogpeople
    Aug 28, 2020 at 14:19
  • I just installed, two good monitors. Having the same issue on Ubuntu 20.04. Had no issue on windows. When I got to a lock screen my monitors shut off and come back on. I suspect it has to do with the lock screen not blanking and the clock changing time. I'll note since you noted a blue light my monitor is the same waking with a bright blue light.. I have an ASUS monitor that is detected as Ancor Communications Inc 24" in display.
    – Brandyn
    Sep 18, 2020 at 18:13
  • im facing similar issue. 3 monitor setup and at random interval it wakes the screens, im suspecting that it is the notifications
    – Belda
    Feb 12, 2021 at 8:22

1 Answer 1


For me the solution was in dconf

/org/gnome/desktop/notifications/show-in-lock-screen : False

see for more https://vitux.com/turn-off-disable-notifications-on-your-ubuntus-lock-screen/

  • Same using gsettings: gsettings set org.gnome.desktop.notifications show-in-lock-screen false
    – S. Kaczor
    Jun 13, 2022 at 17:29

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