Reinstalling Monterey on an M1 Pro MacBook Pro 14"

Install Monterey.app icon

The space bar on my MacBook Pro M1 Pro 14" was binding, so Apple replaced it. But then the fingerprint reader didn't work. So Apple fixed that. Eventually, I got my computer back, but with a 0-cycle battery (yay!) and wiped storage with a fresh install of Venturfa (booo!). I'm not a fan of Ventura and want to use Monterey for as long as I can (I also have three 2015-era machines that max out at Monterey, officially). So...

(All of this was done on a 2015 11" MacBook Air i7, running Monterey, using a double-ended Lexar USB A/C flash drive. The instructions came from Apple, actually. I don’t know why I thought Apple Silicon would be harder to “downgrade” than an Intel Mac; maybe because installing updates on Apple TV devices, iPads, and iPhones, etc., is usually a one-way street?)

Over to Mr. Macintosh for an installer file for 12.6.8.

% curl -O https://swcdn.apple.com/content/downloads/50/44/042-15015-A_XSTTRTW8H4/cu5mniyv6jsu0h806qoqt5qtlu6l7f46w6/InstallAssistant.pkg

% open InstallAssistant.pkg

% sudo /Applications/Install\ macOS\ Monterey.app/Contents/Resources/createinstallmedia --volume /Volumes/Keychain

Then, it was a simple matter of shutting down the laptop, and turning it on holding down the Power key to expose “startup options,” and then selecting Install macOS Monterey from the options provided.

At first go, unsurprisingly, trying to select the built-in storage popped up a message: “The volume cannot be downgraded.” So I backed out of the installer and used Disk Utility to erase the internal storage. Apple really, really wants you to be sure about that:

 

1 of 2 “Erase Mac” confirmation prompts

2 of 2 “Erase Mac” confirmation prompts

Once wiped, an Activation Lock screen popped up: “This Mac is linked to an Apple ID. Enter the Apple ID and password that was previously used with this Mac.” No problem, it’s my Mac and my Apple ID, but I’ve never encountered that before. (Sheltered life I guess.)

Once activated, I was able to select Macintosh HD as the destination and install Monterey successfully. Huzzah!

Installing Monterey onto Macintosh HD