Strange one this. I have a new bare SSD I'm trying to add to my system. When installed in the enclosure I have set aside for this drive it will not show up on my system. To confirm the enclosure is not at fault I installed a mechanical SATA drive and that mounts correctly. To confirm the drive itself is not at fault I installed it in another enclosure and was able to mount and format it correctly. The pairing of this drive with this enclosure seems to be the issue.
So before I last resort to removing an internal drive and swapping with the new SSD, I want to see if there is a formula for testing or making an enclosure work. I noticed the SSD is rated SATA III. The enclosure is Firewire 800 so that gives you an idea of its vintage. Its a solid enclosure by Fantom Drives so its a decent product. Could it be the enclosure is only rated to SATA II or something weird like that. Is there a way around that limitation (firmware?). Or is this just the way it is?
Enclosure is powered by AC/DC adapter, not bus powered. Replacement generic Chinese power brick 11-13V 4-6A.
System: MacPro 3,1 32GB RAM MacOSX El Capitan 10.11.6
Enclosure: Fantom Drives GF500Q
SSD Drive: PNY CS900 120GB SATA III 6Gb/s SSD7CS900-120-RB
Reference Drive: Seagate Momentus 7200.4 500GB