My friend's Macbook Pro Retina Early 2015 turns off abruptly to a black screen (as far as I can tell without logs) after booting. Takes ca. 1 minute. The last thing he remembers doing differently is plugging in an external sound card (but it didn't crash until the next day). Supporting that, audio doesn't work in safe mode and we see no internal sound device in normal mode.

The odd thing is: We can boot into safe mode and it runs fine (except sound). However, when trying to boot into Recovery mode (on disk or online), it turns off before the mode is fully loaded.


The D hardware test says the hardware is fine. In Safe mode, we can run First Aid and it complains "invalid btn_btree.keycount" and "fsroot tree is invalid – which it cannot fix. We could probably fix this in Recovery mode (but can't get in there) or in Single user (but this is Mojave, so doesn't exist).

When trying to boot into Online Recovery mode, it reproducibly: downloads everything, starts booting, then flickers to black once, then shows a beach ball, then turns off.

Things we tried:

  • resetting NVRAM, SMC
  • moving all Kexts in Extensions to the Desktop
  • plugging in the external Soundcard again

Next, our questions are:

  • Can we somehow fix the recovery partition from Safe Mode? Is there another way to run Disk Util (Target Disk?)
  • Can we somehow wipe the SSD and then restore from Time Machine?
  • Will creating a bootable USB stick help? Any reason to hope that this doesn't also just turn off (which seems likely to us given that Internet Recovery does)?
  • There is a new Mojave update which we could try installing in safe mode (but somehow we suspect that won't work/help)

And yeah, warranty is up. The disk is encrypted and has a firmware password. He has a current back-up and no money, so we'd prefer to somehow wipe the disk completely than take it in (problem is we don't know how – target disk mode?).


He took it into a shop and the guy says the logic board gets too hot to touch within 5 seconds, so must be broken. I don't know why that does't leave any shutdown logs. We are guessing safe mode works because it puts so much less stress on the logic board? We were still thinking about killing all sound kexts or something like that, because he cannot afford the replacement.

  • Which Macbook? Did you try Internet Recovery as you may have an issue with the SSD (filesystem or physical)? You could install macOS to a USB drive and boot from that to rule out issue with the internal drive, but it and of itself won't "fix" anything. Also, please clarify what you mean by "going nuclear."
    – Allan
    Commented Feb 25, 2019 at 14:46
  • Edited the post with the requested info @Allan. Already says same problem happened with Internet Recovery. It's clear that a bootable stick would not fix anything, but it might help us fix the disk errors.
    – Ruben
    Commented Feb 25, 2019 at 14:49
  • What makes you think it's a disk issue? If you're having the same issue in Internet Recovery, then it's unlikely to be your disk. Now, are you certain you did an Internet Recovery (download from the Internet) and not boot off the Recovery partition (off your local drive)?
    – Allan
    Commented Feb 25, 2019 at 16:17
  • @Allan I wrote above that Disk utility in safe mode points out an error in the catalog file – that's what I mean by disk issue. Yes, I'm certain that we downloaded from the internet. I did it twice, I had to connect to Wifi and it took longer than regular recovery.
    – Ruben
    Commented Feb 25, 2019 at 16:37
  • So, what you're saying is an image that's downloaded and run from the Internet and doesn't run on your disk somehow exhibits the same issue as every other mode that access your disk with the exception of Safe Mode. That's a major incongruity in this equation. To put it another way, Internet Recovery is the cleanest macOS you'll get. Safe Mode is your same bootable image but without kexts loaded. If you have the issue in Internet Recovery - the problem isn't the disk.
    – Allan
    Commented Feb 25, 2019 at 17:11

1 Answer 1


I would test booting from an external drive running a clean installed OS. If the problem persists, then it's almost certainly a hardware problem. If not, then you are in a good place to repair the issues on the internal disk.

It is odd that Safe Mode works, but Recovery doesn't. I presume this is without the audio hardware attached? What is the audio device? Does it require drivers?

It is certainly worth trying to install the Mohave update (or a Combi installer for maximum restoration of any corrupted system files).

Failing all of this, I would take it to an Apple Store. It might be out of warrantee, but they can still diagnose and fix problems. It's possible, depending on your location, that statutory consumer rights may supersede Apple's own warrantee, if it is a hardware fault.

  • Cheers! Installing the update didn't work – it shut off. Booting from Time Machine also didn't work. I agree it's odd that Safe mode works (yes without audio hardware). I was hoping to learn more about what is disabled there that is enabled in Recovery mode. We will try the external drive but I don't see how it will be better than internet recovery mode. The audio device was an external Traktor mixer and an external audiocard. Left a bunch of kexts, which I disabled. He has no warranty, statutory consumer rights expired also. We would rather try wiping the disk using target disk.
    – Ruben
    Commented Feb 25, 2019 at 16:41

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