I've found a probable cause. xrandr won't enable LVDS1 unless VGA1 is off. So I have to plug in VGA1, and then run:
xrandr --output VGA1 --off xrandr --output LVDS1 --mode 1366x768 xrandr --output VGA1 --auto xrandr --output VGA1 --primary I have to turn VGA1 off, then I can turn LVDS1 on, and then VGA1 on. The xrandr error message is "cannot find crtc for output LVDS1" A bit of googling shows that this happens to more people, with different video cards, on all sorts of versions, with all sorts of Linux distributions. Possibly related, possibly off-topic: I make VGA1 the primary display, because if I don't I can't resize beyond a certain size even though VGA1 is 1920x1080. This may be because VGA1's resolution is higher, and windows are stuck on LVDS1's size. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1071288 Title: No multiple monitors To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1071288/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
