I had some success by simply turning the screen down to 0 by pressing F1, then repeatedly turning it back on (F2) and off (f1) a few times. At first the screen just flickers the goes black, but the more i repeated F1 then f2, the brighter the screen got and the longer it would stay on. Eventually i was able to dance between the buttons and get the screen up to full brightness. This isn't a solution, but it would indicate some kind of software issue is at the root of the problem.