- Feb 26, 2019
Can you share your EFI?Does your USB boot successfully? If so, copy the EFI dir from the USB and paste it into the EFI partition of your HDD/SSD. That's what I had to do in order to finally get mine booting properly.
To view the EFI dir of the HDD/SSD, you need to run a couple of commands in Terminal. In terminal, type "diskutil list" to find the proper identifier for the EFI partition, and then "sudo diskutil mount disk1s1" to mount that partition - your identifier may be different. Mine was disk1s1. Once the EFI partition is mounted, just paste the EFI dir from the USB into the EFI dir of the HDD/SSD and reboot. There are a few extra things that are unneeded but it should work. Mine has been stable for months and successfully updated the OS from the App Store.