Macbook Pro just shut off. Not restarting, just the grey screen
This morning the MacBook Pro was on and I plug in the power cord - it just shut off. I unplugged the power cord and re-started it. A grey screen (& apple logo) appeared, along with a spinning dial. I waited for 5-7 minutes and nothing happened. Not sure what happened.
I tried to 'safe boot' and it didn't work. I don't know what else to do to get the computer started.
Help!
MacBook Pro, Mac OS X (10.4.8)