Resetting the system management controller (SMC) can resolve certain issues related to power, battery, and other features.
The SMC is responsible for managing behaviors related to the following features. If you're experiencing issues with any of these, you might need to reset the SMC.
Power, including the power button and power to the USB ports
Battery and charging
Fans and other thermal-management features
Indicators or sensors such as status indicator lights (sleep status, battery charging status, and others), the sudden motion sensor, the ambient light sensor, and keyboard backlighting
Behavior when opening and closing the lid of a notebook computer
Notebook computers with the T2 chip
Before resetting the SMC, try these steps:
Press and hold the power button for 10 seconds, then release the button.
Wait a few seconds, then press the power button to turn on your Mac.
If the issue persists, follow these steps to reset the SMC:
Shut down your Mac.
On your built-in keyboard, press and hold all of the following keys. Your Mac might turn on.
Control on the left side of your keyboard
Option (Alt) on the left side of your keyboard
Shift on the right side of your keyboard
Keep holding all three keys for 7 seconds, then press and hold the power button as well. If your Mac is on, it will turn off as you hold the keys.
Keep holding all four keys for another 7 seconds, then release them.
Wait a few seconds, then press the power button to turn on your Mac.
Desktop computers with the T2 chip
Shut down your Mac, then unplug the power cord.
Wait 15 seconds, then plug the power cord back in.
Wait 5 seconds, then press the power button to turn on your Mac.