Alright, I'm having this slightly debilitating problem. At seemingly random intervals the screen on my Nexus will shut off, at which point I can still control the screen. For instance if I hit lock then unlock it I can swipe to unlock like I normally do, I can tell because of the haptic feedback. I can also open the camera, which rewards me with a brief flicker of the screen, then blackness again. I have to pull the battery to get it to work again. Any ideas?