某天将MAC笔记本接到外接显示器上，狂点了几下鼠标，结果导致MAC死机。后来，多次外接显示器都是死机状态。查了很多中文帖子都无法得知原因，最后还是英文搜索搜到解决方法如下：
Open up Terminal
If you are using 10.6 and higher
sudo kextunload /System/Library/Extensions/InsomniaT.kext
sudo rm -rf /System/Library/Extensions/InsomniaT.kext
If you are using 10.5 and higher
sudo kextunload "/System/Library/Extensions/InsomniaT (10.5).kext"
sudo rm -rf "/System/Library/Extensions/InsomniaT (10.5).kext"
If you have the old app
sudo rm -rf /Application/Utilities/InsomniaT.app
To remove the preference pane and command line client and uninstaller
sudo rm -rf /Library/PreferencePanes/InsomniaTPref.prefPane
sudo rm -rf /usr/local/bin/insomniat
sudo rm -rf /usr/local/bin/uninstallInsomniaT.sh
Go to System Preferences, right click on InsomniaT and choose to remove the preference pane.
虽然我也不理解其中原因，但是执行sudo rm -rf /System/Library/Extensions/InsomniaT.kext后，确实解决了外接显示器崩溃的问题。
原文：http://peace1221.blog.51cto.com/7425523/1591446