Not sure if this is helpful, but (assuming you are talking about the screen brightness not the keyboard backlit feature) http://askubuntu.com/questions/262003/brightness-not-working-on-lenovo worked for me on a Lenovo Thinkpad X1 Carbon with Ubuntu 13.04.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1098216 Title: Regression in brightness control on Lenovo Thinkpad X230 and X1 Carbon To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1098216/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
