Apple MacBook Pro (13-inch, Mid 2010) - Manual (Page 54)

54 Chapter 4 Problem, Meet Solution
If the screen suddenly goes black or your MacBook Pro freezes
Try restarting your MacBook Pro.
1 Unplug any devices that are connected to your MacBook Pro, except the power adapter.
2 Press the power (®) button to restart the system.
3 Let the battery charge to at least 10 percent before plugging in any external devices
and resuming your work.
To see how much the battery has charged, look at the Battery ( ) status icon in the
menu bar or check the battery indicator lights on the left side of your MacBook Pro.
The screen might also darken if you have energy saver features set for the battery.
If an audio device plugged into the audio port isn’t working
Unplug the audio device. Choose Apple () > System Preferences, and open Sound
preferences. In the Input pane, specify whether you want the port to be used for Sound
Input or Sound Output. Plug the audio device back in.
Note: If you’re running Windows on your MacBook, the port supports only audio output.