Which OSX & Installer to recover my mini I5 2018

[mini5apple]

Unable to recover Mac using online Command Option - R

2100F

Apple Support advised me to go to the apple store and they would help make me a USB recovery stick

Apple Store said…..Sorry for spending ££££ thousands we cant help you DL the correct installer & OSX from a reliable source


Now i’m stuck?

Do i buy a mac use it to download from terminal then return it

Or

Use my trusty reliable windows Dell laptop

No idea where to Download a safe copy of Anything these days

Help would be much appreciated

( Computer newb)

 

[Bigwaff]

Used wired ethernet cable. Don't use WiFi. Internet Recovery flakey over WiFi.

 

[Grumpus]

Used wired ethernet cable. Don't use WiFi. Internet Recovery flakey over WiFi.

Maybe, but maybe not. It could be that Big Sur or newer was installed on the Mini, which has a T2 chip. This updates the iBoot software on the T2, and in my (admittedly limited) experience, once this happens internet recovery will never work again.

 

[Grumpus]

[NOTE: I have never tried this, just passing it along]

This YT video describes the creation of a macOS install USB on a Windows machine using a program called TransMac. It needs a disk image (.dmg) file as input, and unfortunately all the official download sources I know of provide package (.pkg) files. But there is a link in the video description to an archive.org page which allows downloading .iso and .dmg files. I believe your Mini originally shipped with Mojave, and I would download that, since it's much smaller than newer releases. Once you've sucessfully installed Mojave, you can then download a newer macOS from the App Store. Are the images on archive.org safe? I don't know, but if you're truly stuck you might have to take a chance.

 

[Bigwaff]

Maybe, but maybe not. It could be that Big Sur or newer was installed on the Mini, which has a T2 chip. This updates the iBoot software on the T2, and in my (admittedly limited) experience, once this happens internet recovery will never work again.

I have 2018 i7 Mac mini with Sonoma installed and I was just able to boot Internet Recovery w/out issue using Option+Command+R. Took about 10 min using hardwired ethernet, but it booted into Recovery and is offering to install Sequoia, the latest compatible version of macOS.

Also booted Internet Recovery using Shift+Option+Command+R w/out issue and was offered to install Catalina, the version of macOS this Mac mini model shipped with. Took about 5 min using hardwired ethernet.

Of course I did not try to install either as I'm happy with Sonoma, but Internet Recovery certainly downloads and starts. Are you implying that the install of macOS from Internet Recovery fails?

 

[Grumpus]

Are you implying that the install of macOS from Internet Recovery fails?

No, my experience is with a T2-equipped 2019 MacBook Air. After I installed Big Sur, which updated the T2, internet recovery has never worked again - the recovery environment is never loaded. The globe spins for a long while, but then the process dies with code -1008F. The Air has no built-in ethernet port. I have an ethernet dongle which works when booted normally, but it's ignored when booted to internet recovery. Booting from the local recovery partition works when Big Sur or newer is installed, but after reinstalling Mojave, booting with cmd+r immediately launches internet recovery, which always fails.

Thanks for posting your experience. After multiple less-than-helpful conversations with Apple Support, I had the impression that the problem affects T2 Macs in general. Good to know that's not true. I'd still love to find a solution,
since I still run Mojave on the Air (because I still have iPods, and iTunes still works the best for managing them).