How to Troubleshoot a Mac External Hard Drive
External hard drives have been known to suddenly stop working in a heartbeat, so whether you use your Mac for business, pleasure or a hobby, it's important to back up your data and even make a "safety copy" of your backed-up files. While most of today's external hard drives are extremely dependable and experience a very low rate of failure, it's not uncommon for an external drive to go bad for no apparent reason. There's not much you can do to prevent it, so knowing how to troubleshoot a misbehaving drive may pay off.
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Instructions
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1
Make sure that your external hard drive isn't mounting on the desktop because of a logical (not to mention humbling when discovered) reason: Your preferences are set so an external drive does not automatically show up in the finder. To configure this setting, select "Preferences..." under "Finder" in the menu at the top of your screen. Make sure that "Hard disks" under "Show these items on the Desktop" is checked.
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2
Determine exactly what the root of the problem is. It could be a power supply-related issue, a cabling problem or a damaged platter on the hard drive itself. If the power indicator light doesn't come on or you don't hear the drive spinning, it could be a power issue. If the lights come on and the hard drive spins but doesn't mount on the desktop, then it could be a connection issue. Finally, if there is any unusual noise or silence, then it could very easily be the drive itself.
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3
Check all the connections to confirm that they're seated correctly. This includes the power cable, both in the outlet and into the back of the drive. The same goes for the USB or FireWire cable; make sure it's connected firmly at both ends.
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4
Test each component associated with the non-responsive hard drive on a working computer. Attach the drive to a different computer to see if it works and also use different cables and different ports on both computers. If your drive features both USB and FireWire ports, try both ports (but not at the same time). Try a working drive on your computer to confirm that the USB or FireWire port on your Mac isn't defective.
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5
Open "Applications," "Utilities" and then "Disk Utility" if the drive still doesn't respond. Disk Utility is Apple's program to help repair and mount damaged drives. If you're able to select the drive in the left-hand column, highlight it and click on "Repair Disk" under the "First Aid" tab. If the disk doesn't appear in the list of available drives, quit Disk Utility, reboot the drive and launch Disk Utility again.
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6
Try using a commercial disk utility package to attempt to repair the external drive or at least mount it so you can recover any data on the drive. Norton Utilities, TechTool Pro, DiskWarrior and Drive Genius are suitable. Every user has his own opinion of which is the best utility, but they all have the capability to get the job done.
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7
Plan on making a tough call if you've had no luck with Steps 1 through 6. Sending the drive to a data recovery service is never a cheap option; fees for this service can run well into the thousands of dollars, and a premium is charged for faster turnaround. If you have backup of the data on the non-functioning external drive or have decided you can live without it, then throw in the towel and move on.
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Tips & Warnings
Have enough disk space available on your internal hard drive at moment's notice in the event the utility does mount the drive and you have to copy the data onto your internal hard drive.
If the drive does mount, copy the most vital files first, in case the drive quits working in the middle of the file transfer.
The recovery process often takes several hours, so take that into account if you're using a laptop to run the utility, because you'll be tethered to the external hard drive and a power supply for the duration.
Opening the case of an external hard drive voids the warranty in most instances.
Beware of local computer shops that claim to perform data recovery services; many of them simply send the drive to one of the well-known recovery firms and jack up the price.
Resources
- Photo Credit Image 1: Apple, Images 2, 3, 6 7: Chris Capelle, Images 4, 5, 8: MorgueFile.com
