TendStorage guide
External drive not showing up on Mac: check before erasing
Distinguish a hidden Finder volume from a connection or filesystem problem, and protect the only copy before attempting repairs.
Separate visibility from access
Note the drive’s expected name, what it contains and whether it is your only copy. Check Finder’s sidebar settings if a working volume is merely absent there. Then open Disk Utility and choose View > Show All Devices to inspect the device, containers and volumes.
Record what is visible: no device, a device without a mounted volume, or a mounted volume that Finder cannot open. Those are different starting points. A screenshot of the tree can help support, but hide unrelated volume names before sharing it.
Check the physical connection
Apple recommends checking an external drive’s cable, connections and power when it does not appear. Try a known suitable cable and a direct connection where practical. Follow the enclosure manufacturer’s power requirements. Avoid repeatedly disconnecting an active transfer.
If you hear unusual mechanical sounds, see physical damage or repeatedly lose access to irreplaceable files, stop experimenting and seek specialist advice. Decide whether data recovery matters before repair or formatting changes the device.
If the volume is visible but unavailable
Check whether it needs the correct encryption password or has an expected filesystem compatibility limitation. Do not paste recovery keys into a public discussion. Record the exact error rather than assuming a permissions reset or cleaner will solve it.
Understand First Aid before running it
Disk Utility’s First Aid checks and may repair filesystem structures; it cannot detect or fix every disk problem. Apple recommends a current backup first and documents checking volumes, then containers, then the device. Use the linked procedure for the correct order. A startup-disk check may require macOS Recovery.
If First Aid cannot repair a drive, do not casually accept an erase suggestion while it holds the only copy. Choose the recovery route first. A successful check also does not prove every file opens correctly.
After access returns
Copy important files to an independent destination, open representative files and verify the backup before normal work resumes. Tend can review accessible storage and available drive evidence; it cannot make an undetected device appear or recover unreadable sectors.
Sources and further reading
Reviewed October 19, 2026 against the linked documentation. Menu names and capabilities vary by macOS version and device; these guides have not been physically tested on every supported Mac.