Turn on display debug information by running sudo xdiagnose, clicking the first checkbox, apply, then reboot.
Now collect dmesg output, then reproduce the problem and collect a second dmesg. You want the data that's in the second dmesg but not the first. Possibly this bug is related to bug #737891 -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-control-center in Ubuntu. https://bugs.launchpad.net/bugs/840974 Title: configuration of external monitor on laptop does not work properly To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/840974/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
