My external hard drive suddenly stopped showing up on my Mac, even though it appears to power on when connected. It contains important files I need to recover. What steps can I take to access the drive without losing data?
If the drive appears in Disk Utility but not Finder, the problem may be mounting or formatting. If it does not appear in Disk Utility or System Information at all, suspect the cable, power supply, USB adapter, enclosure, or the drive hardware itself.
Start with the low-risk checks: try another cable, port, and powered adapter, then connect it directly rather than through a hub. In Disk Utility, choose View > Show All Devices. If the drive appears, try Mount, but do not erase, initialize, repartition, or reformat it. I would avoid running First Aid immediately when the files are irreplaceable, since repair operations can modify a damaged file system. Check Finder Settings > General and Sidebar too, in case external disks are simply hidden.
If macOS detects the physical drive but cannot mount its volume, recovery software such as Disk Drill for Mac may be able to scan it. Recover files to a different disk, never back onto the failing one. If it disconnects, clicks, spins up repeatedly, or is missing even from System Information, stop powering it on. Software will not fix a mechanical failure, and a professional recovery lab is safer for genuinely important data.
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A power light only means the enclosure is getting electricity, not that the drive is readable. Try it on another Mac before running repairs; if it mounts there, copy the irreplaceable files first and troubleshoot later. A Windows PC can help confirm detection too, but cancel any prompt to initialize or format the disk. If no computer detects it, software such as Disk Drill will not help until the hardware connection or enclosure issue is resolved.
If the drive is physically failing, there may be no safe DIY fix, so treat any successful connection as a brief chance to recover data. Avoid repeatedly reconnecting it, running First Aid, or trying to erase and reformat it. Those actions can make recovery harder.
Open Disk Utility and select View > Show All Devices. If the physical disk appears there but its volume is gray, try Mount once. If it mounts, copy the most important files first. If it stays unmounted, the safer route is to create a byte-for-byte image or clone and scan that copy. Disk Drill can help when macOS detects the device, but save recovered files to a different drive, never back onto the problem disk.
I agree with @smarthacker7552sync that the enclosure or cable needs ruling out, but I would avoid opening the enclosure if the drive is under warranty or uses hardware encryption. Clicking, repeated spin-up sounds, disconnects during scanning, or extremely slow detection are signs to stop. For truly irreplaceable files, a recovery lab is the lower-risk choice.
Before you touch anything else, write down how many times you have already reconnected it. Every plug-in is a roll of the dice on a failing drive, and people burn through their best chance by fiddling instead of copying files the moment it mounts. If it shows up, drop everything and pull the important stuff first. Sort folders later.
The power angle deserves more attention than it got above. A lot of small 2.5 inch drives are bus-powered, and Mac USB-C ports or cheap hubs sometimes can’t deliver steady current, so the drive spins up, browns out, and vanishes. That looks exactly like a dead drive but it isn’t. A short, good quality cable straight into the machine, or a Y-cable that pulls from two ports, sometimes brings a ‘dead’ drive back. Worth trying before you assume the worst.
Where I’d push back a bit is the enthusiasm for First Aid. @smarthacker7552sync and @binaryloop81 already flagged this, and they’re right, but I’d go further: don’t run it at all until your files are safely copied somewhere else. Repair rewrites the file system. On a healthy disk that’s fine. On a marginal one it can turn ‘recoverable with effort’ into ‘gone.’
If it does mount, take one minute to check the SMART status before you trust it. Disk Utility shows it in the info panel, or a tool like DriveDx gives you the reallocated sector count. If those numbers are climbing, treat the mount as temporary and copy fast. Disk Drill fits the same way the others described, useful once macOS can see the device but can’t mount the volume, and better still if you image the drive first and scan the image instead of hammering the original.
One thing nobody mentioned: if the files are genuinely irreplaceable and the drive is clicking or dropping out, stop and price a recovery lab before you spend a weekend on software. Labs are expensive, but so is a second attempt after DIY made things worse.