1. Shut down the Mac.
2. Remove the battery.
3. Press and hold the power button for at least five seconds.
4. Release the power button.
5. Reinstall the battery.
6. Turn on the Mac.

1. Shut down the Mac.
2. On the built-in keyboard (this does not work from an external keyboard), simultaneously press and hold the left Shift, Control, and Option keys while you press the power button for at least 10 seconds. (If you have a MacBook Pro with Touch ID, the Touch ID button is also the power button.) Release all keys at the same time.
3. Press the power button to start the Mac.

If you have an iMac Pro or MacBook Pro model from 2018 with the Apple T2 chip:

1. Shut down the Mac.
2. Press and hold the power button for 10 seconds.
3. Release the power button and wait a few seconds.
4. Press the power button again to turn on the Mac.

As an alternative for the iMac Pro with T2 chip, you can:

1. Shut down the Mac.
2. Unplug the power cord.
3. Wait 15 seconds.
4. Plug in the power cord.
5. Wait five seconds.
6. Press the power button to turn on the Mac.

As an alternative for the MacBook Pro with T2 chip:

1. Shut down the Mac.
2. Press and hold the right Shift key, the left Option key, and the left Controlkey for seven seconds. Continue to hold them down while you press the power button for another seven seconds.
3. Release all the keys at the same time.
4. Press the power button to turn on the Mac.

1. Shut down the Mac.
2. Unplug the Mac’s power cord.
3. Wait 15 seconds.
4. Reconnect the Mac’s power cord.
5. Wait five seconds.
6. Start your Mac by pressing the power button.

Alternative SMC Reset for Mac Pro (2012 and Earlier)

If you have a 2012 or earlier Mac Pro that isn’t responding to the normal SMC reset, you can force a manual SMC reset by using the SMC reset button located on the Mac Pro’s motherboard.

1. Shut down the Mac.
2. Unplug the Mac’s power cord.
3. Open the Mac Pro’s side access panel.
4. Just below the Drive 4 sled and adjacent to the top PCI-e slot is a small button labeled SMC. Press and hold this button for 10 seconds.
5. Close the Mac Pro’s side door.
6. Reconnect the Mac’s power cord.
7. Wait five seconds.
8. Start the Mac by pressing the power button.

Now that you have reset the SMC on your Mac, it should be back to operating as you expect. If the SMC reset didn’t fix your problems, combine it with a PRAM reset. Although the PRAM works differently than the SMC, it can store a few bits of information that the SMC uses.