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USB / external hard drive not recognized on desktop or finder or system report or disc utility after updating to Catalina 10.15.3

Called Apple Care and they could not help after one hour of various resets.


Also, found this not helpful:


https://support.apple.com/guide/mac-help/if-a-usb-device-doesnt-work-mchlp1641/mac


Anyone else have a solution?


Thank you.

iMac Pro

Posted on Feb 4, 2020 12:26 PM

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Question marked as Top-ranking reply

Posted on Feb 4, 2020 1:20 PM

Which Mac do you have? Your profile says an iMac Pro but most people who chose that don't actually have one. As far as your issue, it's highly unusual that no USB drive, flash or otherwise works. Are you plugging them into your Mac or in a USB hub?


I don't know if it was suggested but you could try resetting the SMC.

How to reset the SMC of your Mac - Apple Support

14 replies
Question marked as Top-ranking reply

Feb 4, 2020 1:20 PM in response to PearlGreatPrice

Which Mac do you have? Your profile says an iMac Pro but most people who chose that don't actually have one. As far as your issue, it's highly unusual that no USB drive, flash or otherwise works. Are you plugging them into your Mac or in a USB hub?


I don't know if it was suggested but you could try resetting the SMC.

How to reset the SMC of your Mac - Apple Support

Feb 4, 2020 2:11 PM in response to dialabrain

Essentially on one side you will see a port towards the back of the machine, and a port closer to the front of the machine.

One of them is powered, the other is not. The powered port can take devices that get powered by the computer.

The one that is not, must take the wall charger or devices that get their own charge from another source.



Feb 4, 2020 2:25 PM in response to dialabrain

Underpowered USB ports have been a hallmark of Macs since the early days of USB. One port has more power than the others. Just because the specs don't say it, doesn't mean it isn't there.


What becomes even messier is low power mode from waking up from sleep of a closed lid. Many scenarios there are USB devices that simply won't recognize until a reboot. Although given what PearlGreatPrice has experienced, I don't think that's the issue here.

Feb 4, 2020 2:27 PM in response to a brody

Okay, I think resetting the SMC corrected the problem, which probably was a power problem to the USB ports. (I think that I had tried them all.) I have two on each side. My Mac is a 15 inch with "3.1 GHz Quad Core Intel Core i7" with 16 GB RAM. I need to be aware of which ports are powered - didn't know that and most helpful to know. Thanks everyone. Good work here. Best ~

USB / external hard drive not recognized on desktop or finder or system report or disc utility after updating to Catalina 10.15.3

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