Usb thumb drives not working on Mac

JusVan.exe

macrumors newbie
Original poster
Apr 29, 2019
26
10
Hi all.

I seem to have a really strange issue with my MacBook 12”. I can’t get usb thumb drives to mount on my Mac( doesn’t even show up). However, portable external hard drives show up... I have the Apple usb c digital AV hub that works when I have it plugged into my iPad Pro but not with my 12” MacBook. Any idea what the issue could be?


(All drives are formatted in either exFat or HFS+)
 

barbu

macrumors 6502a
Jul 8, 2013
715
736
wpg.mb.ca
I don't mean to insult, but are you sure it's not showing up? I know the default these days is to not show mounted disks on the desktop. What do you see if you go to Finder > Go menu > Computer ?
 

DeltaMac

macrumors G4
Jul 30, 2003
10,254
2,692
Delaware
You can also check in System Information, then the USB tab to see if the thumb drive is listed there as an attached device.
Also, your Disk Utility will also show your thumb drive as a storage device, in THAT list.
 

colourfastt

macrumors 6502a
Apr 7, 2009
906
747
Not an unusual problem. My version of it started with High Sierra; I can see USB sticks just fine, but not external HDDs. Not with Finder, not with diskutil, etc. And, no, I haven't been able to figure out how to get them to show, and haven't received any advice on how I might go about it. It's rather a shame since both my externals had my backups.
 
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naerct

macrumors regular
Mar 19, 2019
138
25
Southern NH
Not an usual problem. My version of it started with High Sierra; I can see USB sticks just fine, but not external HDDs. Not with Finder, not with diskutil, etc. And, no, I haven't been able to figure out how to get them to show, and haven't received any advice on how I might go about it. It's rather a shame since both my externals had my backups.
Have you tried a clean install of your OS? This would at least pare down software issues. It may be an electrical problem, at least with unpowered drives. I'm assuming you are not using any kind of USB hub, as drives should be connected directly to the Mac. Also what Mac are you using with what OS? Once you have a clean install, you should try a USB drive that has also been reformatted and repopulated, before reattachment.
 

DeltaMac

macrumors G4
Jul 30, 2003
10,254
2,692
Delaware
I have a different take on this: If you can't get certain USB devices to show on your Mac, then you might try connecting that device through a self-powered USB hub. "Self-powered" hub means that there is a separate power supply (wall-wart) for that hub.
 

naerct

macrumors regular
Mar 19, 2019
138
25
Southern NH
I have a different take on this: If you can't get certain USB devices to show on your Mac, then you might try connecting that device through a self-powered USB hub. "Self-powered" hub means that there is a separate power supply (wall-wart) for that hub.
I totally disagree. Once you go to into a hub, you are reduced to much slower speeds, regardless whether it was powered or not. It also needs to be a USB3 hub to get the higher power levels required for some USB3 devices. I had to put my USB3 disk dock on the powered USB3 4-port hub one time, and the spinner got only single digits with the BM speed test as the only device on the hub. That's without needing power from the USB3 port. Your take on this would only tell us if the internal USB is not working, but then, neither would the hub...
THIMK;)
 

DeltaMac

macrumors G4
Jul 30, 2003
10,254
2,692
Delaware
hmm...
I wasn't suggesting a hub as a solution, only a troubleshooting tool.
Sorry if I was a bit unclear about that.
 

harriska2

macrumors 65816
Mar 16, 2011
1,265
639
Oregon
My external hard drives wouldn’t show up to format if I plugged them into a powered usb3 hub. I had to plug it in directly to my mac mini, format, shut it down, plug it into the hub, then it would show up in finder (or anywhere else).
 

colourfastt

macrumors 6502a
Apr 7, 2009
906
747
Have you tried a clean install of your OS? This would at least pare down software issues. It may be an electrical problem, at least with unpowered drives. I'm assuming you are not using any kind of USB hub, as drives should be connected directly to the Mac. Also what Mac are you using with what OS? Once you have a clean install, you should try a USB drive that has also been reformatted and repopulated, before reattachment.
Done and done, multiple times. I even have one external I took straight from the box that the computer won't 'see'.

edit: just for fun I reconnected the externals (this time to my MBA) to see what would happen. Both times the external would power up (and with one I could hear the "heads" scanning the platters) but neither drive mounted—and as I said, one was straight out of the box and has never been written to.
 
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