Tonight my wife tried using the MacBook. It was incredibly sluggish so she rebooted... Except it never came back on. When you press the power button the screen flashes on for a second and goes dark while playing the startup chime. The hard drive grinds for about a minute, then the loading screen with the Apple logo and the little gear comes on for about 30 seconds then it appears to go into sleep mode with the front light pulsing. Pressing any button seems to make it wake up but the screen never actually comes on and it goes back to sleep after 10 seconds. I've tried holding the power button down to make it turn off. I've tried holding the shift key to try and boot into safe mode but same thing. I've tried Apple + Option + R + P, but it just keeps rebooting constantly. If I unplug the power cord when it's in sleep mode it still tries and fails to wake. But if its off and I unplug the power nothing happens at all. I even removed the battery for a couple minutes but nothing. It worked fine earlier today and we just closed the lid like normal. What's going on and how do I fix it?