macOS has a few built-in utilities that help you troubleshoot problems with the OS. Most utilities troubleshoot software related problems but Macs can also have hardware problems. These can be related to your battery if you have a MacBook, or your keyboard, or the temperature management system, among other things. If you’re having trouble with the hardware on your Mac, you can reset the System Management Controller on macOS. Here’s how.
Before you reset the System Management Controller, you should read up on when Apple recommends you should do it.
Reset System Management Controller
The process will differ based on whether or not you can remove the battery from your Mac or unplug it. The newer MacBook models do not let you remove the battery however, if you have an iMac, you can unplug it.
iMac and Mac Mini
Shout down your Mac from the Apple menu. Once it’s off, unplug your iMac or Mac Mini. Wait for 15 seconds. Don’t guess the time. Plug the power cord back in, and wait another 5 seconds before your turn your Mac back on.
With MacBooks, resetting the System Management Controller will differ based on whether or not you can remove the battery.
If the battery cannot be removed, it’s a good idea to let it discharge just a bit. 98% charge will do. Shut down the MacBook from the Apple menu. Once it’s off, hold down the Shift+Control+Option and then the Power button. Keep these buttons held down for 10 seconds, and then release them.
Press the power button to turn your MacBook on.
If the battery can be removed, remove it and disconnect the power cable. Press and hold the power button for 5 seconds and release it. Connect your battery and then turn the Mac on.
Post SMC reset problems
Normally, resetting the SMC doesn’t result in problems however, if your MacBook doesn’t turn on after an SMC reset, or it charges for a bit too long, let it. Wait for the MacBook to finish charging, and then give it a bit more time before you try and turn it on.
If your iMac or Mac Mini won’t turn on, plug it in and wait a while before you try to turn it on again. If it doesn’t turn on even after one hour, you might need to take it in to be looked at. In some cases, the fix might just be that a memory stick needs to be removed and added back. Regardless, you should have a professional check it.