...as additional information, I booted with a live media (Ubuntu 13.10 x64 Gnome edition) and I have connected an external monitor (screen mirroring). The interesting thing is that if I press fn f4/f5 keys, the hud indicator (that is also displayed on the external monitor) shows me brightness icon and the bar going left and right but nothing happens on the laptop screen. Also I tried with: cat /sys/class/backlight/intel_backlight/actual_brightness that initially gives me 4845 and then values change while pressing the fn keys and repeating the above command. So it seems that device is recognized by the system but changes have no effect on the physical device.
Also echo 1000 > /sys/class/backlight/intel_backlight/brightness has no effect. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1243539 Title: Black screen on Dell XPS 13 (L322X) with Ubuntu Gnome 13.10 x64 live media To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1243539/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs