External hard drive not being recognized by my Macbook no matter what I try.

Question

External hard drive not being recognized by my Macbook no matter what I try.

I'm beside myself and am ready to crash out so somebody please come to my rescue.

I have a Seagate 5TB external hard drive that is plugged into a USB converter (USB A to C) that is plugged into the Mac (13-inch M2 Macbook Pro, 2022, with Sequoia 15.6.1).

When plugged in, the external hard drive lights up, so clearly it is connected in some capacity. Just a few months ago I was able to connect it in this same way without a problem. I remember having a similar problem just last month but I was able to unplug it and plug it back in, but this time that isn't working.

Things I have tried:

Checking "external disks" in Finder's sidebar settings.
Opening Disk Utility. There is NOTHING there indicating that an external drive is connected. Not even an "External" section.
Changing out the cable. No success.
Plugging it into another computer. I have plugged the device into my Windows computer, both with and without the USB converter, and the computer immediately recognized it and opened File Explorer like normal, so clearly there are no hardware issues.
Making sure nothing else is set to run at startup.
Restarting the computer. I have done this many times to no avail.
I tried plugging in a different external hard drive, and the same thing happens. I can hear the disk powering on but it's as if the computer doesn't see it at all.
Installing all available updates.

Nothing makes sense anymore; every forum I find seems to be for people who can actually tell that their device is connected in more ways than just the light being on. Any help on this issue would be greatly appreciated. I have many projects that I can only work on with my Mac and this issue is driving me crazy.

MacBook Pro (M2, 2022)

Posted on Aug 24, 2025 11:20 AM

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Answer 1

HWTech

Level 9

66,710 points

Aug 25, 2025 09:23 AM in response to loliana

loliana wrote:

I updated to Sequoia a few days and my SanDisk 2TB (USB-C) will not mount. Tried diff ports on MacBookPro (13" M2, 2022) and on my new Studio Display, diff cables, and nada. Tied restarting with the drive plugged in. Nope. I feel like it is hiding somewhere. I disabled Stacks on the desktop. Cannot see it in the Finder either. But I can see it in Disk Utility. I can unmount from there but still do not see it in the Finder.

Any other tips?

If you are already connecting the drive directly to the computer, then try connecting the drive to a USB3 hub instead. I've seen some users report that this is the only way for them to access their external drive on an M-series Mac supposedly after one of the later Sequoia update patched. Best to use a powered hub to be safe although a couple people reported it was not necessary for them, but why take the chance when purchasing it.

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Answer 2

Aug 24, 2025 11:30 AM in response to suburbanexpl0rer

Even if this drive is formatted NTFS for Windows machine— you suspect you should still be able to read the drive.

For Mac to r/w NTFS you need third party software — if this is the case you can try updating that third party software.

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Answer 3

den.thed

Level 10

88,762 points

Aug 24, 2025 11:39 AM in response to suburbanexpl0rer

How is that external Seagate 5T drive formatted...? (Windows NTFS, FAT32, exFat, Mac APFS)

https://www.easeus.com/computer-instruction/what-format-works-on-mac-and-pc.html?

Try a different USB-C to USB-A adapter between the Seagate and MacBook Pro.

USB-C to USB Adapter - Apple

https://www.amazon.com/dp/B07PDLQ555/ref=sspa_dk_detail_0?

https://www.amazon.com/dp/B08Z768LCW/ref=sspa_dk_detail_1?

https://www.target.com/p/philips-usb-c-to-3-0-usb-a-female-adapter/-/A-79804275

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Answer 4

Aug 24, 2025 12:06 PM in response to den.thed

I tried a different adapter and it miraculously worked. Same brand, just one that I bought 2 years ago. (No idea why the month-old one didn't work but alas.) Also not sure why it worked with the original adapter on my Windows computer. Anyway, thank you for being the only person on the internet to solve my problem.

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Answer 5

loliana

Level 1

11 points

Aug 24, 2025 07:10 PM in response to suburbanexpl0rer

I updated to Sequoia a few days and my SanDisk 2TB (USB-C) will not mount. Tried diff ports on MacBookPro (13" M2, 2022) and on my new Studio Display, diff cables, and nada. Tied restarting with the drive plugged in. Nope. I feel like it is hiding somewhere. I disabled Stacks on the desktop. Cannot see it in the Finder either. But I can see it in Disk Utility. I can unmount from there but still do not see it in the Finder.

Any other tips?

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Answer 6

Aug 24, 2025 07:28 PM in response to loliana

I'm not sure since in my situation I wasn't even able to see it in Disk Utility and it was apparently an issue with the USB converter. Did you make sure "external disks" is checked (not a line) in the Finder Sidebar settings?

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Answer 7

loliana

Level 1

11 points

Aug 25, 2025 12:05 PM in response to HWTech

This is weird. I connected it to my powered Sonnetech hub. No response; not showing in Disk Utility either. Then I plugged it into my MacBookPro, and it mounted. Go figure! Thanks for the suggestion, as it turned out to be a sort of "kick the tires" solution. Hope it stabilizes going forward.

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Answer 8

Aug 25, 2025 03:27 PM in response to suburbanexpl0rer

I have a similar problem. My MacBook can no longer read my 5TB G-Tech AmorATD drive. But when I plug it into my partners MacBook, it reads fine. One difference is that my machine has upgraded to 15.6.1 and hers is running 15.6. Otherwise the machines are pretty well identical. We can both read her 4TB WD drive.

I am relieved that the data is intact on the drive. It will be interesting to see if her machine can read the drive after it updates.

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Answer 9

loliana

Level 1

11 points

Aug 25, 2025 07:58 PM in response to stuartfromtwickenham

One other detail of mine. I opened my photo editing software which has to access the raw photos on the 'phantom' drive. They may have helped mount it on my desktop? Can't say for sure, but is another trick to try if you know what is on your drive and can trigger native software to go looking for it.

Good luck! And yes, no reason I can think of that the drive contents would go missing.

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Answer 10

den.thed

Level 10

88,762 points

Aug 24, 2025 12:25 PM in response to suburbanexpl0rer

You're welcome.

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