MacBook Pro won't start
the progress bar under the apple stops just short of the end and does not complete startup
macOS Sierra (10.12.6)
Apple Event: May 7th at 7 am PT
the progress bar under the apple stops just short of the end and does not complete startup
macOS Sierra (10.12.6)
Try an SMC reset:
https://support.apple.com/en-us/HT201295
Try starting up in Safe Mode:
Use safe mode to isolate issues with your Mac - Apple Support
If neither of those work boot into Recovery and Reinstall Mac OS.
About macOS Recovery - Apple Support
If none of those work make a Genius Bar appointment for a free diagnostic:
Try holding the Option key and then press the Power button (while the mac book pro is off) and see if it boots there.
MacBook Pro won't start