PRAM 재설정
http://support.apple.com/kb/HT1379?viewlocale=ko_KR
SMC 재설정
http://support.apple.com/kb/HT1411?viewlocale=ko_KR
다음 파일들 삭제.
/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist
/Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist
~/Library/Preferences/com.apple.systemuiserver.plist
Reset PRAM
http://support.apple.com/kb/HT1379?viewlocale=en_US
Reset SMC
http://support.apple.com/kb/HT3964?viewlocale=en_US
Delete below files
/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist
/Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist
~/Library/Preferences/com.apple.systemuiserver.plist