jgatto wrote:
I have 4 WD external hard drives, I came home this evening to find out we lost power, I turned on my iMac only to find 1 out of 4 hard drives are mounted , 1 works 1 is lit but not mounted 2 have no lights on and they are all plugged into a surge protector.
That should protect you against spikes, but not dips or power failures, which can damage the directory structure, especially if they were being written-to when the power failed or dipped.
Try
repairing them with Disk Utility (in your Applications/Utilities) folder.
Do yourself a large favor -- get a U.P.S. system. You can now get one with a USB cable that connects to your Mac for under $70. It will run your Mac (and external HD, modem, etc, but
not a printer) for at least a few minutes, and will signal OSX (via the USB cable) when it's switched from utility power to battery, so OSX can do a controlled power-down.
Thus you're protected against both surges and dips in power, and your Mac won't have an abnormal shutdown when they occur.
When you connect the USB cable, you'll get a new set of options in System Preferences > Energy Saver, where you can tell OSX when to do the shutdown -- after a specified number of minutes on battery; and/or when the battery is at a specified percentage; and/or when there's a specified number of minutes left on battery power.