External drives self-ejecting improperly

Rob Sivak wrote:

Both my new 5TB Seagate Portable HDD (TM backup drive), and my new 2TB Samsung SSD (data) USB-C drives are self-ejecting improperly at random intervals from my 4-month old Macbook Pro 16" (running latest MacOS, Sonoma 14.3.1), despite swapping in new cables, switching ports, connecting only one drive at a time, rebooting the Macbook and adjusting the Settings to allow USB connections without asking.

My Apple store tech suggests it could be a USB bus bug on my MacBook Pro and

he's sent it out for a bench analysis, so we'll see...

So why the post?

You can submit your feedabck to Apple—they are not going to read your analysis here

submit your Apple Feedback here: Product Feedback - Apple

I never had your issue, currently I am on 14.3.1 as well..

.I would suspect software incompatibility, not hardware:

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus — does any of that seems applicable to you(?)

all known to cause issues on the macOS

other known third party issue— but not as likely for your issue

third-party sync software like: OneDrive, GoogleDrive, BackBlaze or DropBox

To trouble shoot further you can:

—Test issue in another user (or guest user) account Change Users & Groups settings on Mac - Apple Support

This will tell you if it a universal issue or isolated to your user/admin account. 

—A SafeBoot Use safe mode on your Mac - Apple Support will sort many anomalies

Does a quick disk repair before it fully boots up, and certain system caches get cleared and rebuilt, third party system modifications and system accelerations are disabled.

Login and test. Reboot as normal and test. Caches get rebuilt automatically.

This test will tell you if third party interference; most* extensions etc are not loaded in safe boot mode.

Rob Sivak wrote:

This forum is designed to share Mac user experiences.

Thanks for your thoughtful troubleshooting suggestions.

Just thinking about them all is exhausting!

" My Apple store tech suggests...sent it out for a bench analysis

I do hope you'll post back any insight when your Mac is returned.

Rob Sivak wrote:

My 4 month-old Macbook Pro 16" (M2 Pro; Sonoma 14.3.1) just got a warranted AppleCare bench analysis to diagnose why the laptop was improperly ejecting both of my new external drives, repeatedly and randomly.

On the AppleCare Service Summary that came with my returned laptop, the Macbook Pro's symptoms are described as "Ports/USB-C: Not Charging," another way of defining the interrupted USB connections. There are no other notes on the summary about how they tested the machine. But ultimately,

the techs decided simply to replace my 12-core CPU / 19-core GPU logic board, and the Touch ID circuit, and shipped the laptop back to my home.

Unfortunately, swapping out those core components has not stopped the spontaneous external disk ejections. Now, if I can rule out a software incompatibility, it'll be back to sorting through the hardware variables, like the cables and perhaps the drives themselves.

Does anyone have any suggestions?

the basics are as follows

different port

different cable

different enclosure

different drive and compare your results.

One indicator of a failing drive is it self ejects...

trouble shooting your software was already mentioned above as to how to proceed.