Why won't my Mac recognize my USB flash drive?

Question

Level 1

9 points

Why won't my Mac recognize my USB flash drive?

Background:

Last night, I was downloading a large set of files (33 GB) and writing directly to my USB flash drive. The USB flash drive was working properly. It is a USB 3.0 drive. The computer went to sleep. When I woke it, the computer notified me that the disk had not been ejected properly. When I disconnected the USB drive and re-inserted it, the computer did not make any sounds, and the Finder window did not show that a USB drive had been inserted. I have been trying for hours to remedy this, but nothing seems to work.

MacOS High Sierra 10.13.5

MacBook Pro (Retina, 15-inch, Early 2013)

Troubleshooting:

Over the past 16 hours, I have rebooted at least 20 times. I tried to access the drive under a different user profile. I tried using the flash drive in Safe Boot. I have reset the PRAM and the SMC multiple times each. I have backed up and reloaded the operating system. Nothing has worked so far.

I will be most grateful for any assistance.

Thank you,

Brett

MacBook Pro (Retina, 15-inch, Early 2013), macOS High Sierra (10.13.5)

Posted on Jul 5, 2018 11:04 AM

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Answer 1

Tesserax

Level 10

157,698 points

Jul 7, 2018 3:13 PM in response to bjwheeler

I did look around for other laptops to try the USB drive. Both mine and my wife's work laptops recognized the drive and saw the files on it.

Are both of these laptops Macs as well? If so, then we would know that the version of OS X or macOS on them is not having any issues recognizing this drive ... and that the USB cable is good.

Neither laptop had administrative privileges, though.

... and not having so shouldn't make any difference here. Although I find it hard to believe that your company does not maintain an administrator-level user account on these notebook even if they made it hard to access. Otherwise, you would not be able to add any software ... or maybe that was their intent. Again, regardless, this shouldn't have anything to do with not being able to format or access this USB drive. However, if this drive is encrypted, you would need to know the password to access it.

When I did dig up an older personal laptop to try to format it, the formatting failed multiple times, and I could not delete the drive contents. All I can think is that the drive became damaged somehow, and it cannot be used at all any more.

It is either write-protected, encrypted, or as you have assumed it may be faulty ... but that doesn't explain why the two other laptops were able to access it. Since they can, you could try formatting it with the Disk Utility on either of them before giving up on it.

The drive was a "Gorilla Drive" USB 3.0. I believe it was originally formatted FAT32. The Mac still does not recognize it, and it does not show up in the Disk Utility.

Well, your MacBook Pro model does come with USB 3.0 ports, but this drive should also work with USB 2.0 ports as well ... as it should be backwards compatible.

I have purchased a new USB flash drive. Unfortunately, that seems to be the only resolution for this dilemma.

... and that new drive works in the same USB port on your Mac that you had the Gorilla drive connected to ... correct?

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Answer 2

Tesserax

Level 10

157,698 points

Jul 5, 2018 11:44 AM in response to bjwheeler

It appears that the only thing you haven't tried so far, is to see if you can mount this USB drive on another computer ... did you? Regardless, when connected to this computer, does it show up in the Disk Utility? Was it originally formatted in HFS+ or something else?

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Answer 3

bjwheeler Author

Level 1

9 points

Jul 7, 2018 10:32 AM in response to Tesserax

Hi Tesserax,

Thank you for responding. I did look around for other laptops to try the USB drive. Both mine and my wife's work laptops recognized the drive and saw the files on it. I tried to format the drive, thinking this would help me start over on the Mac. Neither laptop had administrative privileges, though. When I did dig up an older personal laptop to try to format it, the formatting failed multiple times, and I could not delete the drive contents. All I can think is that the drive became damaged somehow, and it cannot be used at all any more.

The drive was a "Gorilla Drive" USB 3.0. I believe it was originally formatted FAT32. The Mac still does not recognize it, and it does not show up in the Disk Utility. I have purchased a new USB flash drive. Unfortunately, that seems to be the only resolution for this dilemma.

Brett

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Answer 4

bjwheeler Author

Level 1

9 points

Jul 8, 2018 9:12 AM in response to Tesserax

Are both of these laptops Macs as well? If so, then we would know that the version of OS X or macOS on them is not having any issues recognizing this drive ... and that the USB cable is good.

Neither of the other laptops were Macs. They were both Lenovo ThinkPads. I agree it would have been good to have another Mac to test, but I didn't have one.

... and not having so shouldn't make any difference here. Although I find it hard to believe that your company does not maintain an administrator-level user account on these notebook even if they made it hard to access. Otherwise, you would not be able to add any software ... or maybe that was their intent. Again, regardless, this shouldn't have anything to do with not being able to format or access this USB drive. However, if this drive is encrypted, you would need to know the password to access it.

The USB drive was not encrypted. Neither of the other two laptops can install programs or software, except by an administrator. The computer settings are tightly controlled by the employer. The Mac is our personal computer.

It is either write-protected, encrypted, or as you have assumed it may be faulty ... but that doesn't explain why the two other laptops were able to access it. Since they can, you could try formatting it with the Disk Utility on either of them before giving up on it.

From the Windows computers, I right clicked on the drive, then clicked "Format." I tried formatting as NTFS, FAT32, and as EXFAT. All times I tried this, the computer looked like it was formatting the drive, then produced an error, saying only that the formatting failed.

... and that new drive works in the same USB port on your Mac that you had the Gorilla drive connected to ... correct?

Yes, this is correct. The new drive does work on the same USB port on the Mac that had the Gorilla drive connected to it.

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Answer 5

Tesserax

Level 10

157,698 points

Jul 8, 2018 9:28 AM in response to bjwheeler

Thanks for all of the additional details ... and based on them, I would have to suspect that the Gorilla drive is faulty. Thanks for your patience in trying to troubleshoot this with me. Sorry we couldn't get it to work for you.

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Why won't my Mac recognize my USB flash drive?

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