I left my computer on last night and I woke up this morning to a full discharge. So, I plugged it in and waited for it to charge for an hour or so. I tried to turn it on - grey screen, I could hear the hard drive but no lights on the front. Then it flashed once on my OSX background and startup programs that are normally there and then dimmed very dark (I can still see the outlines of things but just barely - it looks from a distance like the screen is off). I tried to adjust the screen brightness but no luck. I tried resetting PRAM but that also didn''t work. I haven't installed any new hardware and I'm not sure if the computer might have updated last night while I was sleeping. Any help would be much appreciated.