Welcome to Justanswer.com, my name is ***** ***** I will do my best to assist you.
We may need to try a couple of repairs, and maybe more depending on how the mac behaves after these steps.
Shut down your Mac.
Locate the following keys on the keyboard: Command (⌘), Option, P, and R.
Turn on your Mac.
Press and hold the Command-Option-P-R keys immediately after you hear the startup sound.
Hold these keys until the computer restarts and you hear the startup sound for a second time.
Release the keys.
Will the mac start now?
If not, then shut down again.. Hold down the left shift key.. And then start the mac again while holding down the left shift key.
Will it start now in safe mode? If so, send a reply and let me know as we have a few more repairs we should do.
If it doesnt start in safe mode, also send a reply so we can discuss other steps as needed.
I strive to provide great service, and greatly appreciate a 5 star rating clicked and submitted when you are satisfied.. I always answer follow up questions.
Senior Technician and Network Switching Systems Operator / Maintainer.