Recently i have been experiencing weird behaviors with my MacBook Pro (17-inch, Early 2011), Like the screen going black, inability to wake from sleep, and assorted other headaches. Until one day i needed to restart it i heard the chime and then a grey screen followed by an immediate black screen.
It wasn't responding to an option start or a target mode not even recovery boot.
After researching online i found out that it was a common Mac OS Lion issue, And a lot of Mac users went to Apple stores for repairs and parts where changed without hope, And some others downgraded to SL as a temporary solution until Apple address's this bug, I was going to do so but here is what i did first..
I took my HardDrive out of the MacBook Pro, Put it in a docking station and connected it to another Mac, Opened DiskUtility selected my drive and ran a "Repair Disk Permissions" after it was done i put my drive back in my MacBook Pro and thanks to the LORD it started up normally.
As a precaution i opened "System Preferences" choose "Energy Saver", And unchecked "Automatic graphics switching"