My external hard drive suddenly stopped showing up on my Mac, but it contains important files I need to recover. It doesn’t appear in Finder, and I’m looking for safe troubleshooting or data recovery options that won’t erase the drive.
If the drive appears in Disk Utility, you’re probably dealing with a mounting or file-system problem. If it doesn’t appear there at all, suspect the cable, port, power supply, enclosure, or the drive hardware itself.
Open Disk Utility and choose View > Show All Devices. If the physical drive is listed, select its volume and try Mount. If it mounts, copy the most important files immediately. Don’t click Erase, Initialize, Partition, or accept any macOS prompt to make the disk readable. Those actions can overwrite information needed for recovery.
Before attempting repairs, try a different cable and port, connect directly instead of through a hub, and check the drive’s power adapter if it has one. A different Mac can help separate a drive problem from a USB or macOS issue. If the files are irreplaceable, I’d avoid running First Aid as the first step. First Aid repairs file-system structures, so the more cautious approach is to recover or image the disk before changing anything.
If Disk Utility can see the device but won’t mount it, recovery software may still be able to scan the raw disk. Disk Drill for Mac can create a byte-for-byte image and scan that copy rather than repeatedly stressing the original drive. Install it on your Mac’s internal storage, save the image to a separate healthy disk, and recover files to that separate disk. Never recover them back onto the problem drive. You’ll need free space at least as large as the source drive to make a complete image.
Stop DIY attempts if the drive clicks, repeatedly disconnects, spins up and down, or never appears in Disk Utility with multiple known-good cables. Software cannot fix a mechanical failure, and repeated scans may make a failing drive worse. At that point, a professional recovery lab is the safer option, especially if there’s no backup.
Don’t keep reconnecting the drive or running repeated scans if it drops out, clicks, or takes a long time to spin up. Every power cycle can add stress when the hardware is failing.
The cable checks from @megathread make sense, but there’s a useful check between Finder and Disk Utility: open System Information, then look under USB or Thunderbolt. If the enclosure appears there but no disk capacity or media is reported, the USB enclosure or its bridge board may have failed rather than the drive itself. With a standard SATA drive, testing it in another compatible enclosure or dock can be a relatively cheap next step. Some portable drives have USB built directly onto the drive board, so don’t force anything open unless you know the model and are comfortable risking the warranty.
Keep encryption in mind too. If the disk used FileVault, APFS encryption, or third-party encryption, recovery software such as Disk Drill still needs the correct password or recovery key to produce usable files. Whatever method you try, save recovered data to a different drive, not back to the troubled one.
Not showing in Finder does not mean the files need recovery yet. Check Finder Settings and make sure “External disks” is enabled, then open Disk Utility, choose View > Show All Devices, and see whether the volume is simply unmounted. If the drive appears with the correct capacity, try Mount before running repairs. If it will not mount, create a byte-for-byte image first and scan that image with Disk Drill rather than scanning the original repeatedly.
Everyone’s saying image it first, and that’s correct, but nobody mentioned the catch: to make a full byte-for-byte image you need a spare drive at least as big as the failing one, sitting empty and ready. Plenty of people find that out halfway through when they’ve got a 4TB drive dying and a 1TB spare with photos already on it. If that’s your situation, don’t half-start an image. Either buy the spare capacity first or skip straight to recovering the folders you actually care about most.
The bit I’d push back on slightly is treating this as a data-loss event too early. @silvercoder702 is right that not showing in Finder often means nothing worse than an unmounted volume. Before any of the heavy stuff, check whether the drive is bus powered or has its own adapter. Bus-powered portable drives can flake out on certain Mac ports or hubs simply because they aren’t pulling enough juice, and that looks exactly like a dead drive in Finder. Straight into the Mac, no hub, correct adapter if it has one.
Disk Drill is fine for the scan-the-image step people described, and it’ll read the drive’s SMART status too, which is worth a look before you decide anything. If SMART is throwing reallocated sectors or the thing is clicking like @mr_root warned, imaging attempts can just burn through whatever life the drive has left. At that point the honest answer is that a lab is cheaper than trying twice and finishing the drive off yourself.