Sometimes when I am on my laptop, I'll just close the lid and come back a short while later. When I open the lid sometimes [50%] the laptop won't power back up. I can hear the fans just a kicking and the bottom is pretty hot. If I hit any buttons the laptop will not respond to anything and the fans just spinning away. The only remedy I've been able to get it out of that state is to press and hold the power button until it powers down and then restart it. I'm new to Mac's and it could be user error but I wouldn't expect it to act like that. Please help!