Can't format any USB thumb drive

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Level 10

85,314 points

Can't format any USB thumb drive

I get these Master Boot Record Thumb Drives that will not format as GUID at the drive level, and at the partition level. It claims to succeed at the partition level, but then I can't install an operating system on it because the drive level itself is still master boot record. I try Disk Utility on 10.12, 10.11, 10.6, and same problem. Are these drives being formatted something so totally different in the factory that only 10.13 APFS is going to work? And when I do at the drive level above the partition level, it fails. I have no other message on than failure. And this even from the 10.11 recovery partition's Disk Utility. So I am at a lost, since the recovery partition can't be that corrupted.

Posted on Feb 18, 2018 1:29 PM

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Answer 1

Barney-15E

Level 10

122,318 points

Feb 18, 2018 1:33 PM in response to a brody

In Disk Utility, are you showing the Device list or just the Volumes.

There is a button above the list that allows you to show the Volumes or all Devices. You must show all devices, select the Device, then format it.

I can't remember if that was changed in Sierra or High Sierra. So, if you are seeing the devices and cannot format those, I'm not sure what is wrong.

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Answer 2

Lexiepex

Level 6

14,108 points

Mar 5, 2018 3:22 AM in response to a brody

I would approach this differently:

Either use the terminal way to put an operating system on it, or download DiskmakerX and let this one put the OS on it.

Then the usb disk ends up with GUID Partition table. And then in DiskUtility you can do what you want when you don't want the OS that you just put on it.

Lex

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Answer 3

leroydouglas

Level 10

199,440 points

Mar 4, 2018 11:54 AM in response to a brody

As a goof did you try running Disk First Aid on the drive before you attempt to format/erase ?

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Answer 4

Urquhart1244

Level 10

146,322 points

Mar 4, 2018 3:46 PM in response to leroydouglas

I recall stubborn USB Flash drives that I had to mount-unmount, and format different from what I needed a first time, then a second time with the intended format/scheme.

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Answer 5

Feb 18, 2018 2:25 PM in response to a brody

What happens when you try and erase the volume "Mac" first?

Something you can try, I had some flash drives some time ago that would fail to format but if I immediately tried a second time they would.

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Answer 6

a brody Author

Level 10

85,314 points

Feb 18, 2018 5:05 PM in response to CountryGirl56

I did both ways. And the latest drive did get the format to supposedly work from 10.6, but then 10.11's installer would not complete the installation from internet restore. It just says there was an error.

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Answer 7

a brody Author

Level 10

85,314 points

Feb 18, 2018 1:41 PM in response to Barney-15E

Here I am at the drive level. No matter how I erase it will not remove the Master Boot Record status on it. It complains with an error:

Hitting Erase yields:

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Can't format any USB thumb drive

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