My Mac won’t restart

That is a kernel panic. Does this happen immediately after turning on the computer? If so, then there has been a major hardware failure.

Dealing with Kernel Panics

Disconnect any third-party peripherals including any USB hubs. How to use safe mode on your Mac, Use safe mode to isolate issues with your Mac - Apple Support then boot the computer into Safe Mode: Use safe mode to isolate issues with your Mac - Apple Support and Playing Safe- what does Safe mode do? See Diagnosing problems- crash, freeze, panic, or spinning beach ball?, Don’t Panic! Understanding & Troubleshooting Kernel Panics in macOS, How to fix kernel panics after installing OS X updates | MacIssues, and If your Mac restarted because of a problem - Apple Support.

Kernel panics are indicative of possible hardware failure, so you should Check your Mac with hardware diagnostics or AHT. Kernel panic logs are found in: /Library/Logs/DiagnosticReports/ folder.

If you have no success figuring what is happening then you may need to examine the software you have running when the panics occur. Be sure it’s all current. If you must to resolve the problem erase the disk and reinstall macOS. Follow this outline to reset the computer to the factory-new state: Factory reset of your Mac - Apple Support.

Boot Into Safe Mode

1. If your Mac isn’t already shut down, then shut it down and wait at least 30 seconds before rebooting.
2. Immediately, at or before the chime, press and hold down the SHIFT key. 
3. Release the key after the Apple logo and progress bar appear.
4. Safe mode startup is much slower than normal startup, so be patient.
5. When the Login Screen appears enter your admin password. If you use automatic login, then this means you are in safe mode.

If it is happening all the time, then something has failed. The usual culprit is the disk drive. Not much more to add since I don't know what hardware is involved. If it's a mechanical drive, then it's easy to replace. However, if you have a model with an Apple SSD, that could present a problem because some of Apple's SSDs are not user-replaceable. You can also take the computer to a local Apple shop for a diagnosis to find out the exact problem and how much a repair would cost.

Make an appointment at the Apple Genius Bar for service after the stores re-open. If you need to find an Apple Store - Find a Store - Apple. Also, see How to find your nearest Apple Authorized Service Provider (AASP) or Distributor (AAD). You may also get Apple authorized service at a local Best Buy.

Contacting Apple Customer and Support Service



1. Apple Store Customer Service at 1-800-676-2775 or visit online Help for more information.
2. Primary support help at Contact Support.
3. To contact product and tech support:  Contacting Apple for support and service including international calling numbers.