If you were thinking about upgrading your MacBook or iMac to Apple's just-released macOS Monterey (aka macOS 12), you may want to consider holding off for the time being, as a growing number of users are complaining of bricked Mac computers following the update.
As reported by MacRumors, a significant number of users on Apple Support Communities are finding that their Macs turned off during the macOS Monterey updating process and subsequently would not boot up again.
"I was updating my MacBook Pro from 2018 and it was doing fine until the screen suddenly turned black and now it won't turn on," said one user, echoing the same experience as many others in Apple's forums.
The users' reports suggest the issue is only occurring on Intel-based Macs, meaning all computers which aren't powered by Apple silicon are at risk.
The macOS Monterey update problem follows a similar issue which happened last year, which affected users upgrading to macOS Big Sur.
How to fix a bricked Mac
As with any serious Mac issue of this sort, the best option is often to take your bricked MacBook, iMac or Mac mini to the Genius Bar at your nearest Apple Store.
However, if you're happy to do a little troubleshooting on your own, according to one user in Apple Support Communities, they managed to successfully revive a bricked Intel-based Mac by using another Mac running that's was already running the updated operating system.
The process involves running Apple Configurator 2 and using this to update the firmware on the bricked Intel-based Mac's T2 Security Chip. As most people are unlikely to have a second updated Mac on hand, Apple's Genius Bar staff will be able to do this for you.
A strong word of warning is in order too, as if the revival process is unsuccessful, you may need to use Apple Configurator 2 to restore your Mac, which will unfortunately erase your internal flash storage.
Our advice is to make sure you've backed up your Mac to an external drive using Time Machine before attempting the macOS Monterey update.