Several Mac users are experiencing a bricking issue after updating their machines to the latest macOS Monterey 12.3 update. According to complaints on Apple Developer Forums, and social media platforms, macOS Monterey 12.3 update bricks Mac models with replaced logic boards, including 16-inch Macbook Pro with M1 Pro chip.
Earlier, Mac users reported that macOS Monterey 12.3 update causes performance issues for external graphics cards. Affected users complained that the PCI-E GPU cards are not delivering speed as they normally do, in both eGPU enclosures and Mac Pro after updating their system to the latest macOS version.
A firmware bug in macOS Monterey 12.3 bricks 2021 MacBook Pro models with replaced logic boards
Apple seeded the macOS Monterey 12.3 update to everyone last week with several new features and a bricking issue found in the Monterey 12.3 beta 4. Two weeks ago @jjg08d wrote on Developer Forums that after getting the logic board of their 16-inch M1 Pro MacBook Pro replaced from Apple, Monterey beta bricked their notebook upon restoration.
User @sfriedrich replied that they had a get the logic board replaced when the macOS Monterey 12.3 beta 3 update bricked their laptop and later the Monterey 12.3 beta 4 bricked the machine again and required a logic board replacement.
The cycle is:
You try to upgrade, the upgrade will fail but recovery to handle it correctly, you’ll reboot still on 12.2.1 but with a report a problem dialogue informing you of an iBoot Panic
You’ll try to upgrade again. This time, the iBoot FW will corrupt. You’ll see the apple icon flash on boot 5-6 times before seeing the exclamation mark symbol telling you recovery is needed.
You can try and revive using a second Mac with Apple Configurator 2. This will fail, because it tries to load the 12.3 firmware from the IPSW, in either DFU or Recovery mode.
The only way to get things running again is to manually download the 12.2.1 IPSW and use Apple Configurator 2, with the Mac in DFU mode, to load the revive image. This will update the firmware of iBoot, and the recovery image to a working build. The Mac will then restore 12.2.1’s OS, keeping your data upon finishing.
I’ve submitted as many logs of all this to AppleSeed via Feedback Assistant, but I suspect this will take days to actually get to someone to can acknowledge the issue. In the meantime, there’s going to be many bricked MBPs as most people won’t have a second Mac to preform a revive, and even if they do, won’t understand why that fails as it tries to load 12.3.
There’s seemingly no point going to the Apple Store Genius Bar based on @sfriedrich’s comments. They’ll just do a logic board replacement again which will fail on upgrade.