Chosen Solution
Hi all, I was getting the flashing question mark/ folder recently, so I decided to change the SSD drive. I bought one, and the adapter off amazon, and have installed it. I know I’ve got to create a bootable USB, and I did create a bootable Mojave. When I use the bootable Mojave USB, I can detect the drive, and even install Mojave on it. Great. The problem is that when I unplug the USB, and try to restart the computer, it can never detect the drive again, until I plug in the Mojave USB. If I don’t have the USB in, I get the flashing folder. I’ve tried to hold OPTION when starting without the USB, and the new SSD isn’t there also. Im at my wits end with this one, so any help is greatly appreciated. Thanks!
Using your USB drive to boot up, open your systems preferences, open Startup Disk make sure your internal SSD is selected and then restart, disconnecting your USB drive. Did that work? If you don’t see the internal SSD you’ll need to start again making sure you’ve properly formatted it GUID/HFS+ (Journaled) and re-install the macOS. If that still fails the Adapter/M.2 SSD you got won’t work in your system. Frankly I seen this a few times and have never been able to over come it. At this point you’ll need to return it to get your money back and just get a real Apple SSD or one of the proper 3rd party drives OWC or Transcend.
