The Macbook Pro will not boot. I removed the SSD and can boot the Macbook Pro using a bootable USB stick by holding down the option key at power up. The USB stick has Linux installed on it. This tells me the motherboard is functioning correctly. The SSD is Samsung MZ-JPU256T/OA6.
I have an Other World Computing (OWC) Envoy Pro API2013 SSD to USB3 adapter. I installed the SSD from the Macbook into the OWC adapter and tried to boot by holding down the option key. The EFI boot options do not appear and I assume it is not recognizing the SSD connected to the USB port? Does this mean the SSD is electrically bad or could the boot sector on the SSD be corrupted? Is it possible to determine if it's electrically dead or just a bad boot sector? If so, how? Can I hope to repair the boot sector without destroying the stored data on the SSD?