macbook air stuck on black screen cannot shut down or restart
When I try to wake up my 2011 macbook air 13" I just see a black screen. No cursor. I can't tell if its still asleep or if the screen is just blank. I tried a power shut down (holding down the power button for 10 seconds), but that didn't work. No key combination seems to make any difference. I have tried it plugged in and on battery, but not difference. I can't try a PRAM reset or SMC reset, because I can't get the macbook air to do anything! Help!
MacBook Air (13-inch Mid 2012), OS X Mavericks (10.9.5)