Chosen Solution
Hello, I have a 2012 MacBook Pro Retina Display 15 inch. I had replaced the battery and track pad, and took out the logic board to do so. When I go to turn it on, I type in my password. Then the loading bar loads to about 3/4 of the way. Then it shuts off. It turns back on saying something like “your computer restarted due to a problem.” I can’t start it in safe mode, or when I start it in recovery mode the Apple logo and bar just goes halfway and gets stuck.
Try shift,control,option & power button for 10 Seconds. Do the combination of keys altogether and that should solve the problem.
This sounds like either a bad SSD MacBook Pro 15" Retina Display Mid 2012 SSD Replacement. Or, has a bad OS install, do you have an external drive which you can setup as a bootable drive from another mac system (make sure you are using the same macOS release)
