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2018 MacBook Pro Trials, Travails, and Caveats  


New Member
Joined: 4 years ago
Posts: 2
August 6, 2018 4:42 EDT PM  

This was way too long for the show, and might help some folks, so I thought I would post it here (at Dave's recommendation).

I just had some trials and travails with the 2018 MacBook Pro (i9) that I wanted to share in case anyone else gets caught in the same problem.  As a prelude I will say that I spent a total of 4 hours on the phone with AppleCare (Regular & Senior Advisors) and 2.5 hours at a Genius Bar trying to figure this out.  It was the Geniuses that put me on the right track, but I still had to figure it out myself.

Initial Setup on MBP 2018:

So when I got the machine I was going to migrate everything from my current MacBook Pro (running High Sierra as well, with an APFS boot drive) to the new one.  I made a full backup to an external SSD (USB 3.1), but the new system wouldn’t boot from it so that I could clone to the new machine.  So, I put the new machine in Target Disk Mode, and then used Carbon Copy Cloner to send over the whole thing.

New machine wouldn’t boot, it flipped itself into Internet Recovery.


Trying to get it going again:

So I tried the following steps for a nuke and pave of the new machine:

  1. Tried to boot from a USB installer stick of High Sierra.  Wouldn’t boot from the stick.  Found out about new Secure Boot in High Sierra that requires you to boot into Recovery and set security options to allow booting from external drives and separate options for install disks.  So booted into Recovery and set the option to allow (requires admin user password).
  2. Since I was already in Recovery, wiped the internal drive and tried to install High Sierra from Recovery.  Result: Would go through the initial install screen, but on reboot would automatically boot into a limited Internet Recovery with a message “The Operating System on this Mac needs to be reinstalled,” it would then continue the loop of doing the same thing upon a reinstall.
  3. Tried then to boot from a USB installer stick of High Sierra.  Result: would boot initially and let me wipe the drive and then Install High Sierra, but then would get stuck in the loop above.
  4. After a few different attempts of 1 & 2, called AppleCare and spend 2 hours on the phone with a final recommendation to visit a Genius Desk.
  5. Got an idea and made a USB boot stick of Mojave Beta 4 and managed to install the system. Booted fine, but Migration Assitant told me (Over a Thunderbolt 3 cable with my old MBP in Target Disk) that it would take 128 hours to migrate ~600GB and was moving at about 3MB/sec.  Found online that Mojave Migration Assistant has issues, so cancelled the migration, nuked and paved with Mojave again and resigned myself to manually copying files and re-setting up the machine.
  6. Found out, when I got to the office the next day, that Mojave Beta 4 isn’t working with external monitors (I have a LG 5K and BenQ 4K 27” at the office).  So figured that since Mojave installed I could go back to High Sierra now.
  7. Went back to #2 with the same result. Then tried #1 with the same result.
  8. Tip: Found out during attempts to install that new 2018 MBPs WILL NOT install OS to HFS+ drives (tried that as a workaround).  Even Applecare and Genius were surprised by that.  Disk is greyed out in the installer and give a message of “cannot install to non-APFS drives on this Mac.”
  9. Now I went over to the genius bar.  After 1.5 hours of trying to install (could not replace with a new machine because they didn’t have stock) a senior person came over and pulled my Genius aside and they went in back to look at some troubleshooting articles.  I happen to have GSX access because of work, so I opened up my working machine to look too.  Couldn’t find anything.  Now the two came back and told me that they think that we need to re-flash the firmware IN THE T2 Processor.  Takeaway:  The 2018 MBP (also the iMac Pro) have a DFU Mode for the T2 Processor which handles secure booting and disk encryption (as well as TouchID and other encryption stuff).
  10. They went back to look up how to put the MBP into DFU and now that I had an angle I started looking too.  I was only able to find an article for help on the new DFU mode in the manual for Apple Configurator 2.7.1 (which I could only find in Beta on the developer site at Apple):
  11. They agreed and we followed the convoluted instructions to put the new MBP into DFU, only we couldn’t make it happen.  The machine would just boot every time we tried to do it.  I resolved to have the machine replaced in a few days when they could get stock on my configuration. So I left and went back to my office.
  12. Was on the phone once again with Apple discussing a replacement computer when I figured it out with some Google-Foo.  I read that the new 2018 MBP had a new feature where it would boot when you pressed any key or clicked the keypad.   I put that together with the article that I had read that to reset the SMC on the new MBP you held down the power button only for 8 seconds.  Takeaway: In order to place the machine in DFU Mode you MUST HOLD DOWN THE POWER KEY FIRST, and THEN press Right-Shift, Left-Control, Left-Option.
  13. After 3 seconds of doing the takeaway from #12, the new MBP showed up in DFU mode in Configurator on my old MBP and I was able to restore it (it autodownloaded the firmware it needed) and then booted into Internet Recovery and installed High Sierra.


So here’s my triumphant list of Takeaways:

  1. The 2018 MBP (and iMac Pro) have a T2 Processor with Firmware that can corrupt and result in the inability to install of MacOS High Sierra.
  2. The Firmware restore is included in Mojave Beta Installers, but NOT in High Sierra Installers (yes that includes the special update to solve the thermal problems on the 2018 MBP, which still had to be installed AFTER High Sierra was restored)
  3. To Reinstall High Sierra, you MUST use DFU Mode to restore Firmware first if you have wiped the drive.
  4. DFU is a cast-iron-PITA to get into.
  5. You cannot install High Sierra or Mojave onto an HFS+ formatted boot disk on these machines.
  6. Don’t try to use Beta Migration Assistants, they never work right.
  7. High Sierra and Mojave have new secure boot options that require that they be set in Recovery (or Internet Recovery) mode to allow external boot drives. NOTE: Once you wipe the drive, you CANNOT set this flag from Internet Recovery as there are no Admin Passwords in existence to authenticate with– filed that bug with Radar.

So that’s my story, and I’m sticking to it.  I hope that some of this long, long, long story is usable and helps anyone else that has this problem if they get their hands on a 2018 MBP or iMac Pro.

Don’t get caught (in a loop!).

This topic was modified 2 years ago by PorthosJon

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Joined: 2 years ago
Posts: 1
August 7, 2018 2:38 EDT PM  

I wish i had seen this last week.  went through a similar experience. I'm dismayed that Apple and the Geniuses are totally uneducated about this issue. Ended up (after DAYS of attempting everything you tried and more) they refunded my purchase and ordered me a new one (at a discount "for my troubles"), and now i'm waiting another week for my new MacBook. If they knew about the necessity to reboot into DFU to reflash the firmware, and then of course HOW to do that, we could have saved me a week.

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Joined: 4 years ago
Posts: 7
August 10, 2018 7:17 EDT AM  

Certainly glad i decided after 6 years on my mid 2012 MBP to reinstall from scratch.  No problems here. With most of the stuff in the cloud and the App Store these days it was fairly easy.  As I go along if I'm missing something, I just bring it on board.

Overall though compared to my old machine, 2018 has warp drive.  A $44 adapter handles my card reader and USB ports and a Conmdex power adapter gives me a travel charger.  Battery life is great even with heavy Photoshop/Lightroom use. The Keyboard seems fine to me but I'm not a heavy typis and I even like the taskbar. Puts many common commands for programs at easy reach.  

I'm sold



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Joined: 4 years ago
Posts: 2
August 10, 2018 9:44 EDT AM  

That's exactly where I was Dave.  Sorry you didn't have a genius that dug for you.  I hope it turns out ok and you get your replacement!