Como redefinir um MacBook Air ou MacBook Pro
Continue holding the keys until your Mac finishes starting up. Your Mac may reboot itself during this process. Once you arrive at the user selection screen, you can release the keys and sign into your MacBook Pro like you usually do. You may need to reset some of your preferences (e.g., preferred audio output) after resetting the NVRAM.
How to reset a MacBook Air or MacBook Pro 1. Hold down the Command and R keys on the keyboard and turn on the Mac. Let go when the Apple logo pops up.
In order to reset the SMC, you'll need to hold down the ⌘ Command, ⌥ Option, and ⇧ Shift keys all at the same time while also holding down the "Power". button. If your MacBook Pro has a touch bar, the "Power" button is also the Touch ID button. Press and hold the SMC reset keys for 10 seconds.
Once the Disk Utility is closed, the Mac OS reinstallation window will present. Pick Reinstall MacOS or Reinstall OS X, you MacBook Pro will start connecting to Apple servers and downloading the Mac OS automatically through Wi-Fi network or Ethernet. The Mac OS version reinstalled depends on the key combination that you used in step 1.