Formatted USB flash drive in Disk Utility, now it won't show

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Level 1

4 points

Formatted USB flash drive in Disk Utility, now it won't show

I am trying to help my mother bring her old but still working 17-in MacBook Pro up to date with OS X (she's on 10.5.x).

In order to install OS X 10.6 (as a precursor to later OSs), I tried to format a USB flash drive with a plan for a GUID partition as instructed online, onto which I would put a disk image of the OS installer.

However, I formatted the USB drive as Mac Extended (journaled) and could not find the GUID option in Partition, so I reformatted as Mac Extended (case sensitive) and now the drive does not show either in Finder or in Disk Utility.

The USB drive was fine before. Now it looks like Disk Utility has ruined it.

Any solutions?

MacBook Pro, Mac OS X (10.5.6)

Posted on Jan 21, 2016 5:57 AM

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Answer 1

BDAqua

Level 10

239,177 points

Jan 21, 2016 10:45 AM in response to danp65

You don't want Case Sensitive at all, but can DU still see the drive or not?

Do other USB thing get seen in that port?

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Answer 2

danp65 Author

Level 1

4 points

Jan 21, 2016 11:33 AM in response to BDAqua

Thanks for the reply, BDAqua.

Strangely, I tried again just now after a few hours and it showed.

I tried reformatting as MS DOS and it let me add a GUID partition, so have now restored the disk image to it and am about to try the installation.

I have no idea why it wasn't showing earlier on 2 computers anywhere, but hey...

THIS THREAD IS CLOSED

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Answer 3

BDAqua

Level 10

239,177 points

Jan 21, 2016 12:39 PM in response to danp65

OK, good luck! 🙂

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Answer 4

danp65 Author

Level 1

4 points

Jan 21, 2016 12:46 PM in response to BDAqua

Thanks.

Just in case you can help, the laptop didn't recognise my USB startup disk.

It was formatted MS DOS, it had a GUID partition and I restored the disk image to that in disk utility. But when I option+startup it only shows the Mac hard drive. 😟

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