HT1338: OS X: Updating OS X and Mac App Store appsLearn about OS X: Updating OS X and Mac App Store apps
Currently Being ModeratedOct 17, 2012 9:58 AM (in response to jrdefrancisco)
Did you 'replace/ugrade' the internal hard drive or did you simply USB plug-in an external drive?, I ask because you mention you 'installed' it. If you installed a new hard drive then the system will not bootup because the drive is blank, in that case you would need to install a system from DVD disc or a USB flash drive that has a Mac system. If its an external drive plugged into the USB slot, obviously you simply need to remove the drive and your system should be back. If there is no light activity..no power then its a major issue in which a computer tech needs to look at it.