I found a workaround in my case: https://askubuntu.com/questions/1167445/monitors-do-not-enter-powersave-sleep-mode-after-screen-blanking/
Changing the input setting from *auto* to *hdmi* on my AOC monitor fixed the problem. It seems monitors can *poll* the graphic card (CEC?): that way the computer somehow responds by waking up all monitors. I consider this stil a bug. Not sure if this is a gnome-screensaver bug, but it is a nasty one (wasting energy). IMHO Ubuntu should be able to turn of monitors (powersdave mode) with default factory setting. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-screensaver in Ubuntu. https://bugs.launchpad.net/bugs/1292041 Title: Lockscreen doesn't turn off the screen Status in OEM Priority Project: Fix Released Status in OEM Priority Project trusty series: Fix Released Status in Unity: Fix Released Status in gnome-screensaver package in Ubuntu: Invalid Status in unity package in Ubuntu: Fix Released Bug description: [ATTENTION] This bug report is strictly for lockscreen. When user activates lockscreen with Ctrl+Alt+L or Super+L shortcut or from indicator-session the screen should blank off after a couple seconds. The new Unity lock screen doesn't turn off the monitor screen. I can wait as long as 10 minutes after activating the lock screen and the monitor still doesn't turn off. Then when I unlock the screen and don't use mouse or keyboard monitor will turn off (it's about 5 seconds after unlocking). To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1292041/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp