macOS Sonoma Boot Failures

What happened?

macOS Sonoma and macOS Ventura 12.6 were released with multiple serious bugs in their upgrade and boot process. Combined, these bugs can create conditions where a machine always boots to a black screen, no matter what power button press combination is used. This leaves users stuck, and the only solution is to use DFU recovery.

This situation can happen with certain settings on certain models, when multiple macOS versions are installed side by side (one Sonoma, one earlier). Since Asahi Linux behaves as if it were macOS 12.3/12.4/13.5 (depending on model and installation time), dual-boot installs of macOS Sonoma and Asahi Linux have the same effect. For macOS 13.6, this situation doesn't even require a dual-boot system, and can be triggered stand-alone as the only installed OS.

What are the bugs exactly

There are two bugs:

• macOS Sonoma upgrades sometimes (often) fail to upgrade System Recovery. This leaves the system in a usable state, but with possibly no or a broken recovery fallback OS. This means that if the system cannot boot into the Paired recoveryOS for whatever reason, it can no longer be recovered. macOS 13.6 upgrades are also affected, as they actually install the macOS 14.0 Sonoma SFR.

• For 14" and 16" models: Once System Firmware is updated to the macOS Sonoma version, if the display is configured to a refresh rate other than ProMotion, that system will no longer be able to boot into older macOS installs nor Asahi Linux correctly. This includes recovery mode when those systems are set as the default boot OS.

What happens if I get hit by the bug? Will I lose data?

You will need another Mac to recover from the fault using DFU mode. However, you will not lose data.

What machines are affected?

All machines are affected by the first bug (failure to update System Recovery).

MacBook Pro models with ProMotion displays (14" and 16") are affected by the black screen boot bug.

What versions are affected?

• macOS Sonoma 14.0 and 14.1 (not fixed as of 2023-10-31)
• macOS Ventura 13.6 (uses 14.0 firmware)
• Possibly: macOS Monterey 12.7 (unconfirmed)

What should I do?

I have not upgraded to macOS Sonoma (or macOS Ventura 13.6) yet and I want to

We recommend waiting until these issues are fixed by Apple before upgrading. If you want to risk it and you have a 14" or 16" machine, make sure the display refresh rate is set to ProMotion before attempting the upgrade. You might still end up with a corrupted System Recovery, which can only be fixed with DFU mode or a subsequent successful upgrade.

Regardless of whether you plan to install Asahi Linux or not, we recommend running the Asahi Linux installer after a Sonoma upgrade to check the status of your System Recovery partition. It will inform you about any issues prior to the main menu, before any changes are made to your system.

I have not upgraded to macOS Sonoma (or macOS Ventura 13.6) yet and I'm in no rush

Feel free to stay on macOS version 13.5 or earlier for the time being. You can safely install Asahi Linux if you wish.

I have already upgraded to macOS Sonoma and I want to install Asahi Linux

The Asahi Linux installer has been updated to check the version of your System Recovery, and will refuse to install if there is a mismatch. Therefore, it is relatively safe to install at this time. It will also inform you if you are vulnerable to the ProMotion display issue.

Start the installation process normally. If the installer informs you that your System Recovery is damaged when you attempt the install, that means you will have to wait until a further system update that resolves the problem before you can install Asahi Linux. Follow the prompts carefully and read all the text.

I have already upgraded to macOS Sonoma and I have Asahi Linux

If you are currently booted into macOS, ensure the display refresh rate is set to ProMotion (for 14" and 16" machines).

We recommend running the Asahi Linux installer again to verify the integrity of your System RecoveryOS partition and ProMotion status. If there is a problem, you should refrain from making any major changes to your system until the issue is fixed by Apple.

I am affected to the issue, what do I do?

If your machine boots to a black screen (brief Apple logo, then nothing), first attempt a regular recoveryOS boot by fully powering down the machine, then holding down the power button.

If that does not work, try booting into System RecoveryOS. To do this, fully power down the machine, and then perform a fast "tap-and-hold" power button gesture (press and release once, then press and hold).

If that also leads to the same problem, unfortunately you will have to resort to DFU mode. See the following section for details.

If you can successfully reach a boot menu, select your macOS Sonoma install and hold down Option while confirming your selection to make it the default boot OS. If you have macOS 13.6 ventura instead, follow the special section below.

How do I fix my machine with DFU mode?

First, you will need another Mac running a recent version of macOS (an Intel Mac is OK). Install Apple Configurator from the App Store on the other Mac and open it.

Follow Apple's instructions to connect your two machines together, and put your target machine in DFU mode. The target machine's display should remain off at this point.

You should see a large "DFU" icon in Apple Configurator. If you see anything else, the machine is not in the correct mode. Repeat the procedure and try again.

Once you see the DFU icon, right click it and select Advanced → Revive. This will begin the revive process.

If you get a message saying "A system update is required for this device", you can ignore it and press "Restore Anyway". This process has been tested with another Mac running macOS 13.5.

Follow the prompts and accept any accessory connection requests. Do not leave the machine unattended, as you might miss one of those prompts (and there is a timeout). The process will take a few minutes to complete.

Once the Revive process completes, the machine should boot into macOS Recovery. Follow the prompts and authenticate yourself.

After this, the machine will reboot into the Boot Picker.

If you have macOS 13.6 ventura instead, follow the special section below.

Select your macOS Sonoma install, then go into the Display settings page and set the display refresh rate to ProMotion. This will prevent the problem from reoccurring.

Should you wind up with a "black screen boot" again after this point, follow the steps in the previous section to perform the "tap-and-hold" power gesture. This should now work properly, as your System RecoveryOS has been updated. You may then select macOS again and fix the display refresh rate.

I don't have another Mac to use DFU mode! What do I do?

You can take your Mac to the Apple Store and ask them to do a DFU Revive. Make sure they do not do a Restore, which would wipe all your data. They should perform this service for free. Do not let them charge you any money for it. This is a problem Apple caused, and purely a software issue. If the technicians claim there is hardware damage, they are wrong.

What if I have macOS 13.6 Ventura and not Sonoma?

macOS 13.6 Ventura uses the macOS Sonoma System Firmware, but suffers from the problem. Even users with just 13.6 installed single-boot are affected by this issue (no Asahi Linux needed). We do not understand how Apple managed to release an OS update that, when installed normally, leaves machines unbootable if their display refresh rate is not the default. This seems to have been a major QA oversight by Apple.

If your system has 13.6 Ventura and ended up in the black boot situation, unfortunately the only known solution is to upgrade to Sonoma. From the Boot Picker, select Settings. This will boot into recoveryOS. From there, select "Install macOS Sonoma". Follow the prompts and select your existing macOS volume. This will upgrade macOS without losing your data.