I can also confirm this on a ThinkPad T540p with stock kernel (3.13.0-generic), and that the workaround is to drop into a console to adjust brightness and then go back to X.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1291371 Title: thinkpad screen dims after unplugging external display, and won't re- brighten without leaving X To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1291371/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
