MB unable to access backup drive???

[nhcowboy1]

MB: early 2025 MB Retina
OS: Mojave
Connection: Apple USB-C --> USB-A adapter --> USB-A cable that came with the backup drive

Initially tried using Disk Utility to format and partition the backup drive - no luck.

Tried again with a formatted and partitioned backup drive — the MB recognizes each of the three partitions in the backup drive, but is absolutely unable to access them. Even something as simple as a small text document couldn't be transferred from the MB to the backup drive. Attempting to transfer data to the backup drive resulted in error code -50.

Was also unable to eject the backup drive - had to use "forcible eject" to remove each of the three partitions.

Troubleshooting:

(1) On the macbook - used the same Apple USB-C to USB-A adapter with a mouse. No problem - worked brilliantly!

(2) Also tried the same backup drive with a different Mac - had no problem formatting, creating partitions, transferring data, etc.

So, I know the backup drive works and I know the macbook's adapter works . . . so why can't the macbook communicate with the backup drive???

Edited to add: It should go without saying, but the backup drive was formatted using Mac OS Extended (Journaled).

 

[Fishrrman]

First thing I'd try is a different cable.
Is the cable you're using now "detachable from" the backup drive?
If so, get a USB-c cable (MB end) to USB-a cable (drive end). No adapter.

 

[nhcowboy1]

Yes, the cable is detachable, but the connection to the HD enclosure is not a USB connection. To be honest, I have no idea what it is. It's the other end of the cable that's a USB connection.

Also, as noted above, I have confirmed that the original cable works (by testing the backup drive with another computer) and that the macbook's USB-C --> USB-A adapter works (by testing it with different USB-A accessories).

 

[hobowankenobi]

Yes, the cable is detachable, but the connection to the HD enclosure is not a USB connection. To be honest, I have no idea what it is. It's the other end of the cable that's a USB connection.

Also, as noted above, I have confirmed that the original cable works (by testing the backup drive with another computer) and that the macbook's USB-C --> USB-A adapter works (by testing it with different USB-A accessories).

Need to solve that mystery first. Pixs?

 

[DeltaMac]

It would also help if you can tell us about any identifying info on the external drive, such as brand and model number.

 

[nhcowboy1]

Sabrent "Hard Drive Docking Station"
Seagate "Barracuda" 2 TB hd

How do I upload a picture?

Not sure the relevance of any of this, since it's all working just fine on my Mac Mini.

Perhaps it's an issue with the MB OS, and I should reinstall? Was able to backup data from the MB just fine a few days ago (using a different backup drive that I don't have available at the moment), immediately prior to upgrading to Mojave. Makes me think it may be a problem with Mojave . . .