Apple released a fix for Snow Leopard users experiencing the “Intermittent black screen or loss of video” issue. The company released a fix for Lion users in October, and this release brings Snow Leopard users up to date on the problem, too.
Black Screen MacBook Pro Issue
Apple’s patch notes simply say, “This update addresses an issue where MacBook Pro (15-inch Mid 2010) computers may intermittently freeze or stop displaying video.”
You can find the update on Apple’s support site as a standalone download. If you have a qualifying MacBook Pro and are running Snow Leopard, you’ll find the download in Software Update.
Lion users who somehow missed the fix for that OS can download it from Apple’s support site.