A few days ago my spouse's MBA started showing problems. At first it wouldn't turn on at all, showing an orange indicator on the MagSafe charger. After resetting the SMC a couple times and letting it charge for a long time it booted up.

It showed the regular login screen but it wouldn't complete the login, it'd just sit on the end of the progress bar.

I tried booted in recovery mode, single mode, internet recovery mode, and afterwards a freshly made USB macOS Mojave installer I made on my MacBook Pro 2018.

None of the above complete the boot up. Instead, it sits forever on the 100% progress bar. I started the Mojave installer in verbose mode and I see an "Unsupported CPU" and "Unsupported PCH" in the log.


I was able to boot up a live Ubuntu USB and everything seems ok. I installed the Ubuntu on the main disk to see if there was a problem with the disk at all. Ubuntu runs just fine on the MBA.

Any ideas on what else can I try?


While the "Unsupported CPU" and "Unsupported PCH" messages in the log appear concerning, I wouldn't jump to the conclusion that this is what's causing the problem. The fact is I've seen these messages before in Macs that run perfectly fine.

I see you've already reset the SMC, but you haven't mentioned resetting the NVRAM and this is something you should also do.

Reset your NVRAM

For your model MBA you'll need to follow these steps:

  1. Fully shut down your MBA
  2. Press the power button and then press the commandoptionpr keys. You have to make sure you press these keys before the gray screen appears or it won’t work.
  3. Hold those keys down until your Mac reboots again (i.e. wait until you've heard the startup chime a second time)
  4. Let go of the keys and let your MBA reboot.

It's not clear to me if you still have macOS installed or not:

  • If not, then shut down your Mac again and switch it on and immediately press the option key and let me know what drive options (if any) appear on the screen.
  • If so, what happens when your MBA boots up after the NVRAM reset?

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