My external hard drive suddenly stopped showing up on my Mac, but it contains important files I need. Disk Utility does not seem to recognize it. How can I recover the files without formatting the drive or losing data?
The key missing detail is whether the drive appears in System Information under USB or Thunderbolt, even if Disk Utility cannot see it. Hold Option, open the Apple menu, choose System Information, and check the relevant connection section. Recovery software cannot scan a drive that macOS does not detect at the hardware level.
Before doing anything destructive, try a different cable, port, and powered adapter if the drive needs one. For a desktop drive, confirm that its power supply is working. You can also test it on another computer. Do not click Initialize, Erase, Partition, or reformat it. I would avoid repeatedly running First Aid too, especially if the drive disconnects, makes clicking sounds, or takes a long time to spin up.
If System Information sees the physical drive but its volume will not mount, recovery software may still be able to read it. Install Disk Drill for Mac on your Mac’s internal drive, not the problem drive, and scan the external device. Recover files to a separate healthy drive. If the option is available and the disk is unstable, creating a byte-for-byte image first is safer than repeatedly scanning the original.
If the drive does not appear in System Information with multiple known-good cables or computers, this is probably an enclosure, USB bridge, power, or internal drive failure rather than a damaged file system. A replaceable enclosure can sometimes be the whole problem, but opening some portable drives is risky because the USB connector may be built directly onto the drive board. Clicking, beeping, failure to spin, or constant disconnecting are signs to stop testing and use a professional recovery lab if the files are important.
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Check Time Machine and any cloud-sync service before powering the drive up again; you may already have usable copies of the important files. If it is the only copy and the drive clicks or repeatedly disconnects, skip recovery software and take it to a recovery lab.
Was that drive encrypted? Nobody has asked yet, and it changes everything. If you had FileVault turned on, or the drive was formatted as encrypted APFS or with a third party lock, recovery software can read raw blocks all day and still hand you scrambled garbage without the password or recovery key. Track that key down before you spend hours scanning. Same goes for hardware-encrypted enclosures where the chip that does the decryption lives in the case, not on the drive. If that bridge dies, the raw disk is basically noise even in a pro lab.
The other thing that matters is whether this is a spinning drive or an SSD, because the advice splits hard there. @byteengineer1232 is right that clicking or spin-up trouble means stop and call a lab, but that only applies to mechanical drives. If it’s an SSD that dropped off the bus, there’s no clicking to warn you, and repeated power cycles can be worse for it than for a platter drive. SSDs also do their own garbage collection, so the window to recover deleted data can close faster. Different failure, different rules.
On the software point, I wouldn’t ignore the tool mentioned above, but keep expectations low for a drive that Disk Utility can’t even see. Disk Drill and anything like it need the disk to show up at the hardware layer first. If System Information lists the physical device but not the volume, fine, scan it, and yeah, image it first if the connection keeps dropping. If nothing shows in System Information across two cables and two machines, no app is going to save you and you’re into enclosure swap or lab territory.
One cheap thing worth trying before you assume the worst: plug it into a different Mac running a different macOS version. I’ve seen threads where a volume that refused to mount on a newer system came up fine on an older one, or the reverse, usually an APFS version mismatch. Costs you nothing and it’s non-destructive. If it mounts even once, copy the important files off immediately and don’t trust the drive again.