This morning I wanted to turn on my MBP but all i can hear is the very slight hum of the hard drive. The screen remained black. I closed the lid and would be able to see the light on the side of the MBP light up. A this point I knew it wasnt dead. So I troubleshoot, I began by holding down the power button to completely shut off the system, which it did. Then I press the power button again, and the computer magically came back to life. My question for you mac gurus is how do I prevent this from happening again? does it sound like a hard drive issue? Logic board issue? I will buy whatever internal replacements it needs but I just dont want a repeat of this mornings problems cause I missed my bus. Thank you in advance. UPDATE: The power plug was plugged in and the battery indicator on the side was roughly half full.