gavspav wrote:
My 2015 Macbook Pro has died - I think it's a logic board failure and I want to try to recover the data from the drive. Unfortunately it is a 16+6 proprietary fitting (SSD) and the cheapest external enclosure for it is slightly more than I want to pay.
My son has a 2014 MBP with the same SSD fitting but obviously his machine won't boot from my SSD (I tried it!)
macOS is very particular in which SSD is used in each Mac. Even though the SSD is physical & electronically compatible, macOS knows there is a difference and refuses to work. The funny thing is a non-Apple OS like Linux will work perfectly fine with the SSD installed in the different Mac...I personally tried it on an SSD which macOS refused to boot.
What I'm wondering is, if I made a bootable USB drive, would I be able to put my SSD in his machine, boot from the external drive and then save my data?
Maybe. But from my own personal experience when I encountered the issue of "incompatible" SSD, macOS would refuse to boot even from the installer when the incorrect SSD was installed internally. With another somewhat incompatible SSD, macOS would sort of work enough to do what you want.
Unfortunately OWC is one of the very few vendors who make an enclosure for the Apple OEM blade SSDs. Sometimes OWC may have a used or Open Box item available for a bit less than a new one.
In the future make sure to always have frequent and regular backups of your computer and all external media (including the cloud) which contains important & unique data. With the 2016+ USB-C Macs, there are a lot more ways of permanently losing access to your data even without a hardware failure. Plus if the SSD had failed, then it would be extremely difficult or even impossible to recover any data...it would definitely be more expensive than the cost of an external USB3 backup drive. macOS includes the Time Machine backup software for free, you just need to supply an external drive.