Getting files back

A drive that will not mount

Updated 2026-07-31 · 4 min read

A drive absent from Finder is usually visible somewhere lower down, and where it appears tells you the fix.

Is it a display setting?

The drive may be mounted but hidden. Finder → Settings → General and Sidebar → ensure External disks are ticked. Check the Desktop too (General tab → Show these items on Desktop → External disks).

Is it in Disk Utility?

Disk Utility → View → Show All Devices. Three outcomes:

• Not listed at all → hardware: cable, port, power, or the drive itself
• Listed but greyed out (not mounted) → select it → Mount. If mount fails, run

First Aid

• Listed and mounted but not in Finder → the display setting above

Show All Devices matters — it reveals the physical disk even when its volume will not mount, which distinguishes "drive dead" from "filesystem damaged".

Filesystem damage

A drive that appears but will not mount often has directory corruption — common after an unsafe eject. First Aid repairs many cases. If it mounts read-only afterward, copy your data off immediately before attempting anything else.

Format the Mac cannot read

A drive formatted for Windows (bare NTFS) mounts read-only or not at all without extra software. Disk Utility shows the format; if it is unreadable, another machine may be needed to reformat or offload it.

Hardware checks, in order

1. Different cable — the commonest single cause, especially with USB-C
2. Different port
3. Direct connection, not through a hub
4. Powered drives: confirm the power supply
5. Another Mac or a PC — isolates drive from computer

The data-first principle

If the drive mounts at all, even read-only, even briefly — copy the irreplaceable files off before running repairs. First Aid can make a struggling drive worse; a copy made while it still mounts is worth more than a perfect repair that never comes.

Common questions

Why is my external drive not showing on my Mac?

Check Finder's sidebar settings first, then Disk Utility with Show All Devices. Greyed-out means unmounted; absent entirely points to cable or hardware.

My drive mounts read-only — what do I do?

Copy your data off immediately. Read-only usually means filesystem damage or an NTFS format; back up before repairing.