So I'm in a rather strange situation. I have an SSD, and I am using a SATA to USB 3 adapter (basically an enclosure, as it is called) to connect it to my laptop. This worked fine with a mid-2012 MacBook Pro.
I tried to use this SSD with with a retina late 2012 MacBook Pro, only to find that it wasn't recognized at all by the MacBook. It didn't show up in the Finder, in Disk Utility, or even in the "System Information" USB section. It seemed as though it wasn't even connected. The USB ports on the MacBook are functional.
I tried formatting it with macOS Journaled, exFAT, and even NTFS, but to no avail. I decided to see if this would happen with other MacBooks. I connected it to another retina MacBook Pro, and it wasn't recognized. I connected it to a MacBook Air, and it was. When I formatted it to exFAT I connected it to a Windows computer, and it was recognized (and that's how I tried formatting it as an NTFS drive).
As some additional information, when I connect the SSD to the MacBook Pro, the enclosure light lights up, meaning that power definitely goes to it. However, it doesn't blink at all (which would suggest some operations were going on).
So from this, although I haven't tested an exhaustive list of computers, it seems as though the SSD won't work with newer, retina MacBooks. Is there any explanation for this? Is there any way in which I could make it work again? Is there a problem with my SSD, the adaptor, the USB 3.0 Micro-B 10 Pin to USB 3.0 Type A wire that I am using? Or is there a problem with newer MacBooks in general which don't allow such SSDs to be connected to the laptop with this adapter (which seems like the most likely of these)? Are there any drivers I need to install for it to work? (This doesn't sound likely, though).
Has anyone here had any luck with connecting an external SSD to their (retina) MacBook Pro?
diskutil list after connecting the external SSD, as was suggested by Allan in the comments, gives this output:
/dev/disk0 (internal, physical): #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *121.3 GB disk0 1: EFI EFI 209.7 MB disk0s1 2: Apple_CoreStorage Macintosh HD 120.5 GB disk0s2 3: Apple_Boot Recovery HD 650.0 MB disk0s3 /dev/disk1 (internal, virtual): #: TYPE NAME SIZE IDENTIFIER 0: Macintosh HD +120.1 GB disk1 Logical Volume on disk0s2 XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX Unencrypted
This is the same output that I get when I don't have the SSD connected.