MacBook Pro (15-inch, Mid 2010): Intermittent black screen or loss of video

Apple has determined that a small number of MacBook Pro (15-inch, Mid 2010) computers may intermittently freeze or stop displaying video on the built-in display or on an external display connected to the MacBook Pro. In this situation, you may also see a restart warning message before the video is lost or the display turns black or gray. Affected computers were manufactured between April 2010 and February 2011.