I have a MacBook Pro laptop. When I turned off the alarm it just went black. I tried to restart it but it was unresponsive. After 2 hours I was able to restart it but it has since been randomly blacking out or parts of the screen will be blacked out.
iMac, OS X Mountain Lion (10.8.3)
The startup disk may need repairing ...
Restart your Mac while holding down the Command + R keys. From there you should be able to access the built in utilities to repair the startup disk if necessary, or restore OS X using OS X Recovery
Be aware, OS X Recovery requires a high speed broadband connection.
You have a hardware problem. That could be the hard drive or one of the other electronic components inside your Mac. Your best option is to take the system to an Apple store to be properly diagnosed as to the cause of the problems you are having. If you are still in the warranty period these failed parts will be replaced for free. If you no longer have any warranty then they will give you an estimate on the cost of the repair.
My laptop has just shut down and won't power up
