We recently had a customer performing a logic board swap on a 2012 13" Retina MacBook Pro and we ran into a very interesting problem. I think our discovery was useful, so I thought I would share.

Our customer installed his original SSD and the system would not boot or recognize the installed SSD. After a phone call and a lot of trial and error, we realized the issue was the File System.

The SSD had macOS Mojave (10.14) which we reasoned was using the new Apple File System (APFS), which was introduced with High Sierra (10.13). It turns out the board we had sold was never used with High Sierra and therefore did not have the needed Firmware update.

Thankfully, our customer had a Time Machine backup of their Mac and we were able to walk them through the internet recovery, reformatting and restoring the drive using Time Machine. 

This solution should apply to all Macs using SSDs that originally shipped with macOS Sierra (10.12) or lower.

It's also a great reminder of how easy and useful Time Machine can be.