MacBook Pro screens flicker/blink

Some owners of unibody (Late 2008) MacBook Pros have experienced an issue in which the laptop's screen will suddenly start blinking.

Apple Discussions poster Hoojiemoster writes:

"My computer had a hard time digesting all of the new messages being added in Mail. Everything slowed down temporarily and Mail disappeared and was inaccessible. When it finally reappeared with the new emails, I noticed the intermittent blinks."

This problem seems to be relatively random, although, for some users, it seems to have started after a period of heavy workload. It may occur only once or twice, but for some users, the blinking happens rapidly. This is clearly an issue with the MacBook Pro only, and has something to do with the graphics drivers trying to manage the dual GPU setup. Non-pro MacBooks do not have this issue, and it only happens on the MacBook Pro when users are utilizing the GeForce 9400M integrated GPU, which gives it the same graphics configuration as the non-pro MacBooks.

This problem will most likely need to be addressed by Apple in a software update, but until then users may try the following:

Potential Fixes

Reset PRAM Reset the computer's parameter RAM by rebooting and holding the options-command-P-R keys until the machine cycles through a few restarts. Then let the keys go and allow the machine to boot properly.

Reset and adjust display settings Go to the "Displays" system preferences and toggle between a few resolution settings. Additionally, users might try clicking the "Detect Display" button.

Workaround

Currently the problem seems to disappear when users run off the dedicated GeForce 9600M processor, and it is recommended to do this unless battery conservation is of the utmost importance. Using the dedicated graphics processor will also increase the computer's performance. To do this, go to the "Energy Saver" system preferences and check the option to enable "Higher Performance" graphics. This will only take effect after a logout and login again.

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