Mac won't turn on after a power cut? What to check

MacUpdated

If your Mac won't turn on after a power cut, start with Apple's steps for a Mac that doesn't turn on: check the power cable and socket, press and hold the power button for about 10 seconds, then unplug every accessory and try again. If the Mac turns on but stops at a symbol or a blank screen, Apple has separate steps for that.

Quick answer

Check that the power cable is undamaged and plugged into your Mac and a working socket. Press and hold the power button (or Touch ID) for about 10 seconds, then press it normally. Unplug accessories and try again. If it starts but sticks on a blank screen, start up from macOS Recovery and run Disk Utility.

What should I check first?

Apple's steps for a Mac that doesn't seem to turn on start with the power supply, then the power button, then accessories.

  1. Make sure the power cable is undamaged and plugged securely into your Mac and a working electrical socket. If you have another compatible cable or power adapter, try it.
  2. If your Mac has no built-in display, make sure the external display has power, is connected to the Mac and is turned on.
  3. Press and hold the power button for about 10 seconds. On a Mac laptop with Touch ID, press and hold Touch ID. Then press and release the power button normally.
  4. Unplug all accessories, including printers, drives, USB hubs and phones, then repeat step 3.
  5. On an older Intel-based Mac, Apple says resetting the SMC may help. A Mac with Apple silicon doesn't need this.

If it still doesn't turn on, Apple says it may need a service.

What if it turns on but doesn't start up?

If you see a flashing question mark, a circle with a line through it or another symbol, Apple says your Mac is turned on but isn't starting up, and each symbol has its own fix. A black, grey or blue screen is normal for a moment during startup. If it stays there:

  1. Press and hold the power button for up to 10 seconds until the Mac turns off, then turn it on again.
  2. Start up from macOS Recovery. On a Mac with Apple silicon, keep holding the power button as the Mac turns on, release it when you see "Loading startup options", click Options, then Continue. On an Intel-based Mac, press the power button, then immediately hold Command (⌘) and R until you see an Apple logo or spinning globe.
  3. In Recovery, use Disk Utility to repair your startup disk, then restart.
  4. If the blank screen comes back, start up from Recovery again and reinstall macOS.

If your Mac with Apple silicon or the Apple T2 Security Chip won't start from Recovery, Apple says you might need to revive or restore its firmware.

My Mac says it restarted because of a problem

Apple says that when a Mac starts up again after a problem forced it to restart or shut down, you may see a message saying the computer restarted because of a problem. Unexpected restarts, Apple says, are usually caused by installed software or connected devices. Its checks:

  1. Install all available software updates.
  2. Use safe mode to try to isolate the cause.
  3. Shut down, disconnect peripherals such as hard drives and printers, then use the Mac for as long as it usually takes for the restart to happen. If that fixes it, reconnect one device at a time.
  4. If disconnecting devices doesn't help, use Apple Diagnostics with the devices still disconnected.

Should I run First Aid after a power cut?

First Aid in Disk Utility is Apple's tool for checking a disk, and one of its steps for a Mac stuck on a blank screen. Apple says it can find and repair errors in the formatting and directory structure of a storage device, and that significant errors may stop a Mac starting up completely. Make sure you have a current backup first.

  1. If you're repairing the startup disk, or the Mac won't start up all the way, start up from macOS Recovery and choose Disk Utility. Otherwise open it from Applications > Utilities.
  2. Choose View > Show All Devices.
  3. Select the last volume on the device, click First Aid, then click Run.
  4. Work up the sidebar, running First Aid on each volume, then each container, then the device itself.

If Disk Utility finds errors it can't repair, Apple's next step is to erase the disk.

Check your Time Machine backup

Time Machine makes hourly backups for the past 24 hours, daily backups for the past month and weekly backups for older months. Once your Mac is running, choose Back Up Now from the Time Machine menu in the menu bar, then use the same menu to check the date and time of the latest backup.

If there's no backup disk set up yet, in macOS Ventura 13 or later go to Apple menu > System Settings > General > Time Machine, click Add Backup Disk, choose the drive and click Set Up Disk.

Can a desktop Mac turn itself back on when the power returns?

Some can. Choose Apple menu > System Settings, then click Energy in the sidebar. Apple lists an option called "Start up automatically after a power failure", which starts up your Mac after a power interruption. Apple notes that some options aren't available on every Mac.

On a Mac mini introduced in 2024 or later, a Mac Studio introduced in 2025 or later, or an iMac introduced in 2024 or later, running macOS Tahoe 26.5 or later, Apple documents a "Start up when power is connected" menu with three choices:

  • Never: you press the power button to turn the Mac on.
  • After power failure: the Mac turns on when power is reconnected, if it was on before the power failure.
  • Always: the Mac turns on whenever it's connected to power.

If the Mac has stayed connected to power since it shut down, Apple suggests waiting about 30 seconds between disconnecting and reconnecting power to turn it on.

To protect the Mac from what can happen when the power comes back, see how to protect electronics from a power surge, and for the rest of the house, what to do in a power cut.

Where Failshot fits

Your password is the first layer. Failshot is the second, for the moment someone sits down at your Mac and unlocks it: while it's on, it photographs whoever unlocks your Mac, then, with Pro, records a 5-second video, and its window tells them the unlock was photographed. With the Mac's built-in camera, the green light comes on.

With Pro, turn on alerts and Failshot emails you about an unlock you don't confirm as yours, a wrong Failshot PIN or answer, or its camera access being switched off while it's on. Switching it off, or quitting it from its menu, takes Touch ID or your Failshot PIN and answer, never your Mac password.

Failshot for Mac is out now at failshot.app, for macOS 14 or later. Free to download. It's free to use. Pro adds video, email alerts and the encrypted vault, and you can try Pro free for 7 days. Your card is taken at sign-up and charged on day 8 unless you cancel. iPhone, Android and Windows versions are coming soon.

More questions

Can my Mac shut down by itself when running on a UPS?

Yes, on a desktop Mac. In System Settings > Energy, Apple lists UPS Options, which set the time or battery level at which your Mac shuts down when it's using an uninterruptible power supply.

Do I need to reset the SMC after a power cut?

Only on an older Intel-based Mac, and only as one of Apple's steps if it won't turn on. Apple says you don't need to reset the SMC on a Mac with Apple silicon.

Will Disk Utility delete my files?

Running First Aid checks and repairs the disk. Apple still says to make sure you have a current backup first, because if Disk Utility finds errors it can't repair, the next step is to erase the disk.

My Mac still won't turn on. What now?

If the power checks, the 10-second button hold and unplugging accessories don't work, and an Intel Mac's SMC reset doesn't help, Apple says your Mac may need a service.

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