how to reset smc for mac air 2015

How to reset the SMC of your Mac - Apple Support

Notebook computers with a nonremovable battery

This applies to MacBook Pro models introduced in mid-2009 through 2017, MacBook Air models introduced in 2017 or earlier, and all MacBook models except the MacBook (13-inch, Mid 2009).

1. Shut down your Mac.
2. On your built-in keyboard, press and hold all of these keys:

• • Shift  on the left side of your keyboard
  • Control  on the left side of your keyboard
  • Option (Alt)  on the left side of your keyboard

1. While holding all three keys, press and hold the power button as well.
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4. Keep holding all four keys for 10 seconds.
5. Release all keys, then press the power button to turn on your Mac