Target Display mode may not work after waking from sleep

Sometimes after waking a portable computer from sleep that is connected by a Mini DisplayPort to Mini DisplayPort cable to an iMac (27-inch, Late 2009) in Target Display Mode, the image from the iMac appears on the iMac screen instead of the image from the portable.

This article has been archived and is no longer updated by Apple.

Download and install the 27-inch iMac SMC Firmware Update 1.0 to address this issue.

Learn more about using a 27-inch iMac as an external display, also known as Target Display mode.

Last Modified:

Additional Product Support Information

Start a Discussion

in Apple Support Communities
See all questions on this article See all questions I have asked
United States (English)