Reinstalling High Sierra on late 2016 MacBook Pro from External Backup


New Member
My MacBook Pro is currently at Restart Computers(on a tech’s recommendation) awaiting a new motherboard, keyboard and speaker assembly.
I have a full bootable backup done via “Superduper!” As of the morning I took the laptop in for service. The backup is of “High Sierra” as I wasn’t quite ready to move to “Mojave” as yet ... possibly by next month.

My question/concern is that I suspect that the motherboard is going to come with “Mojave” pre-installed. “Superduper!” would need to erase the SSD before it copies from my external backup. Would this pose any problem for me? Is there anything hardware or software wise that would prevent me from erasing “Mojave” and installing “High Sierra”. If so, how do I get all my data which is under “High Siera” on the external backup on to the now new blank machine running “Mojave”?

This is all assuming that the new motherboard comes with “Mojave” pre-installed ... if not then it’s a pretty simple process from what I have researched and I can upgrade to “Mojave” when I am ready afterwards.

In case you are wondering what problems I was having and for anyone else that maybe experiencing the same:
The right speaker would emit a crackle and pop and the sound would be muffled. Sometimes if the audio was a low conversation everything would be fine until a louder sound was encountered and then the same crackle/pop. Switching channels and the problem stayed with the physical right hand speaker. The problem didn’t occur while using headphones.
The other problem started happening after I updated “Safari” and “Security” on July 23rd. Kernel panic and ‘computer restarting due to a problem’ message. Some other weird things also started happening. I rest SMC/NVRAM/PRAM, rebooted the machine from “Sierra” and “High Sierra” before the “Safari/Security” updates and also rebooted using “Mojave” on a flash drive and same issues.
Fortunately Apple Care is still good until December 2019 ... keeping my fingers crossed and hoping someone can advice as to my concerns above. I don’t have another machine to install my backup on and use it to migrate to the new one and even if I did, I don’t know how.
Thanks in advance.


Well-Known Member
Assuming this is all being done by an Apple-certified tech, the machine should be returned to you with the same data and OS version that was on it when you brought it in. Motherboards do not have OSes installed on them -- that like all your other data resides on your drive, which is not one of the parts being replaced. I'm so glad you made a bootable backup before sending it off, but in this case it will "hopefully" be unneeded.

As for Mojave, it is about to be replaced with Catalina this fall. I would advise upgrading to Mojave before Catalina comes out, as Apple stops making the previous OS available for download pretty quickly after the latest one comes out (with the exception being for users whose machines cannot accept the new OS version).


New Member
Thank you Chas. So far so good! ... things seem to be working well. Need to complete some testing, moving things about and then should be ready to upgrade to "Mojave".
One little concern ... the first reply I got from the forum had no suggestions but a lengthy ad for "Essay Erudite" for custom writing services. Very annoying when one is waiting for relevant information but get solicited instead.
However, thanks again for your help and suggestion.