Comment 165 for bug 1303736

Yeah, either this is not fixed, or there are multiple issues that manifest in a similar way. I'm running 14.04 in 64-bit mode, fully up to date, on a Dell notebook with nVidia FX 2700M video card. I have added the lines in /etc/systemd/logind.conf:

    HandlePowerKey=ignore
    HandleSuspendKey=ignore
    HandleHibernateKey=ignore
    HandleLidSwitch=ignore

so that theoretically the power management features are only managed by light locker now. I have xfce configured to never suspend the computer. Display is configured to blank after 10, turn off after 15 minutes, and locker is set to lock the screen whenever the screensaver is enabled.

When I close the lid, it locks the screen with light locker, and my display turns off. When I reopen the screen some time later, the lock screen appears and I can unlock with my password. Then the screen goes black.

In some cases, the shortcut key bound to 'xrandr --output LVDS-1 --auto' will bring the screen back to life. In other cases, no amount of hammering the shortcut key will wake up the display. I'm forced to emergency sync/reboot with the magic SysRq key. I'm not sure what's different, except that it seems less likely to turn on again if it's been a while since I've used the computer.

Like Claude, the xfconf-query command returns false. I have done the 1a and 1b steps from the earlier comments. I haven't found any messages in syslog around the time of these events, so there's not a lot I can do to further debug the problem, it seems.