Here’s what to do if there is no startup disk on your Mac

Are you trying to boot up your Mac and notice the dreaded question mark inside a folder icon on the screen? Sometimes it appears for only a few seconds, and then your Mac boots normally. But it can also stay there, not letting your Mac boot. Such an error happens when your Mac cannot find a startup disk. Here are a couple of things you can do to fix it.

What to do if there is no startup disk on your Mac

If you see the question mark for a few seconds

When this happens, the first thing you should do is reset your Mac’s NVRAM.

  1. Shut down your Mac.
  2. Press the power button and hold down Command-Options-P-R.
  3. When your Mac plays a startup sound, release the keys after it sounds a second time (If your Mac has a T2 security chip, release the keys after the Apple logo appears and disappears a second time.)
  4. Once your Mac has booted, ensure the correct startup disk is selected (see below).
Tip:

There are several reasons why your Mac may not be able to detect the startup disk. It can be either software or hardware issues. To minimize that possibility, Mac users should run regular maintenance for their Macs to keep top-level performance.

And listen, I don't mean you have to take it apart and clean the components! No, I mean software maintenance, such as reindexing Spotlight, repairing permissions, and running regular maintenance scripts.

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If the question mark doesn’t go away

You’ll need to boot your Mac in Recovery mode and try to repair the disk with Disk Utility.

  1. Shut down your Mac.
  2. Press the power button while holding down Command-R.
  3. Release Command-R when you see a spinning globe, Apple logo, or another startup screen. Type in your admin password.
  4. Choose Disk Utility from macOS Utilities and click View. Then choose Show all Devices.
  5. Click the down arrow next to Macintosh HD, select the volume, and choose First Aid in the toolbar. Click Run.

After all the steps are completed, repeat for the next volume up. And if the disk repairs successfully, don’t forget to restart your Mac.

If Disk Utility can’t repair the disk, you will need to reinstall macOS.

  1. Quit Disk Utility to return to macOS Utilities.
  2. Choose Reinstall macOS.
  3. Follow the on-screen instructions to reinstall macOS.

If Disk Utility doesn’t show your disk in the sidebar and macOS Utilities can’t reinstall macOS, you will have to book a repair with Apple or an Authorized Service Center.

How to choose the startup disk

If you reset the NVRAM to fix a problem, you should check if the correct startup disk is selected.

  1. Click on the Apple menu and choose System Preferences.
  2. Choose Startup Disk.
  3. Click the padlock and type in your admin password.
  4. Select the disk to startup from.

What to do if you accidentally delete your startup disk

If you somehow managed to delete your startup disk, you will need to reinstall macOS after restarting in Recovery mode. If you deleted the Recovery partition, your Mac would use Internet Recovery to reinstall. You will need to be connected to the Internet.

How to reinstall macOS

  1. Follow the steps above to restart your Mac in Recovery mode.
  2. Choose Reinstall macOS from the macOS utility menu.
  3. Follow the on-screen instructions and type in your admin password if asked.

If your Mac can’t see its startup disk, don’t panic! Follow the steps above, and you should be up and running again in no time.

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