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User profile for user: cheffner
cheffner Author
User level: Level 1
0 points

USB Thumb Drive not readable by this computer.

I have a USB thumb Drive that I use for my Macs, and I was transferring a file from an older macbook to my 2011 Macbook Pro, which is something I have done before with no issues, but now I get this message. I have read up and everyone says use Disk Utilities and Disk Warrior, yet I am having no luck whatsoever. One thing that I have noticed is that the people that are posting about it and that have had luck with these two utility programs is that they have another option that says "Initialize" Below is a screen shot of the message that pops up everytime I insert my USB drive into my computer.

User uploaded file

If I open Disk Utilities I see the USB drive on the list but I cannot do anything with it. Here is a picture of what comes up if I try to restore it.

User uploaded file

So what do I do next? Would it be better for me to just junk the USB thumb drive and get a new one or is there some sort of fix to this. I hope someone can help me out here. Thanks in advance!

MacBook Pro, OS X Mountain Lion (10.8.4)

Posted on Jun 23, 2013 9:18 AM

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User profile for user: leon-geyer
leon-geyer
User level: Level 1
31 points

Aug 27, 2017 8:42 PM in response to cheffner

I found 2 ways to solve this kind of problem.

As you see in your DiskUtility, your disk (or device) has no Volume (you can see that in Waynes screenshot there is a subbranch, inside of the device "generic flash" there is a volume called "No Name" - that case is different). So it looks as a problem not of Format (Journaled, Fat32) , but of Partition Scheme (GUID, Master Boot, etc).


When diskutil did not work, I repaired disks trough Terminal (with Command Line). And found that often I can't reformat a disk because it can't be ejected. For that, after trying with diskutil and sudo, I had success with force = sudo diskutil unmount force and then the other parameters (google diskutil if unknown, for example have a look at http://www.theinstructional.com/guides/disk-management-from-the-command-line-par t-1).

If that does not work, there is another option, more violent - but well, before throwing your USB into the trashcan, it can be a solution: make it forget its partition scheme. In case of a corrupt GUID-Scheme, sudo gpt destroy /dev/disk(your disknumber) worked for me. The article I found said that for MBR the command is sudo frisk -i -a hfs /dev/disk(disknumber), haven't tried that. https://www.heise.de/ct/hotline/Mac-Partitionsschema-zuruecksetzen-2662601.html (in german)


Always, and as so many times repeated in this forums: if using Command line be very very careful. And don't forget to always start with a diskutil list to avoid formatting an unintended Disk (like your Harddrive).


Good luck!

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User profile for user: Wayne Contello
Wayne Contello
User level: Level 7
26,613 points

Jun 23, 2013 9:43 AM in response to cheffner

Chef,


You will want to select the device on the left, then the "Erase" segment at the top:


User uploaded file


At this point you will want to select the format form the menu titled (you won't believe this), "Format". Make sure to select the format that will work all computers you plan to use the drive on. If you never plan to use with Windows then you don't have to use FAT. If you want to use with Windows then use FAT.


Regards,

Wayne

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User profile for user: cheffner
cheffner Author
User level: Level 1
0 points

Jun 23, 2013 9:53 AM in response to Wayne Contello

Unfortunately, like I said, I cannot do anything with the disk in Disk Utility, it either comes up as failed or won't let me chose anything.

User uploaded file

So as you can see, (you won't believe this) I can't chose any of the options under format.

Thanks for the reply


Any other solutions that you think might be helpful?

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USB Thumb Drive not readable by this computer.

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