problems turning on
might require a reset
of the SMC
If the battery is nonremovable:
- Shut down your Mac.
- Unplug the MagSafe or USB-C power adapter from your computer.
- Using the built-in keyboard, press Shift-Control-Option on the left side of the keyboard, then press the power button at the same time. Hold these keys and the power button for 10 seconds.
(If you have a 2016 MacBook Pro with Touch ID, the Touch ID button is also the power button.)
- Release all keys.
- Reconnect the power adapter.
- Press the power button again to turn on your Mac.