MacBook Air 5,2: 2012, screen power management, shuts LCD off permanently
Running Kubuntu 12.04 64 bit. Everything works BUT if I let the LCD screen go to sleep, it goes black and no key or mouse movement wakes it back up. In strong light at an angle, I can see my screen just barely enough to find the menu in order to shut down. Terminal is visible but no way to read in order to type anything into it so I can't reasonably "echo" anything into /sys or /proc to manually bring it back. Odd issue. Since it is a laptop, disabling power management seems to be a drastic workaround. I have been using the 'buntus since 6.06 and I have seen resume from sleep issues, but the machine did not sleep and I have never seen anything like this. Oddly, the keyboard backlight stays on.
I pushed the slider to 60 minutes, but still had "dim" display after 5 minutes. This happens in 5 minutes, so rather than dim, it permanently disables it.