Chosen Solution
I recently replaced a failing logic board on a 2011 Macbook Air. The install went smoothly, but on start-up, I get the question mark symbol indicating that the SSD isn’t being recognized. However, when I boot into Recovery Mode, it sees the SSD just fine and even lets me verify/repair. The hardware test also recognizes the drive and gives the computer a passing grade. I suspect this is a firmware issue. The Macbook Air was running High Sierra, but I have no idea what the firmware situation was on the replacement logic board. I don’t know how to update the firmware if I can’t boot into the OS. Any advice on how to update it?
Reboot the system and hold the Option key to get to the startup manager. You could be able to then select the SSD as your boot drive. It you are able to get it to boot up then you just need to go into the Startup disk settings to alter it.
