Dying(?) Mac Mini (7,1 _ late 2014) not recognising USB boot installer

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Dying(?) Mac Mini (7,1 _ late 2014) not recognising USB boot installer

My Grandma has a Mac Mini that is failing to start up. The "snail" as she calls it gets about half way along and then stops and won't boot, even if left overnight etc. Unfortunately the history of this poor machine is that my Grandpa, who has Alzheimer's and is paranoid about fire, would turn it off at the wall whenever he saw it on and whatever the machine might happen to be doing at the time...

So I am looking for some help seeing if I can bring it back to life or if they just need to go buy something new.

I have tried all sorts (resetting nvram, trying to boot to safe mode etc) but I am pretty sure it is a hard disk issue. If I boot into recovery or internet recovery, I get the 4 options but none of them work. In Disk Utility I can't check the health of anything as it says hit can't unmount the drive because it's in use. Same thing with erase etc.

If I click to reinstall Monterey, it just hangs with the beachball for hours.

So I tried creating a Monterey USB installer from my 2016 MacBook Pro. That seems to have gone ok, but when I try to boot with what I think is the Option button, nothing happens - it just goes to the "snail screen". I only have windows keyboard available but I am pretty sure I am hitting the right key as I had to use the Option key in some of the other startup keyboard combos I tried. It is the Alt key next to the space bar, but I have also tried the Fn key second from left at the bottom.

I feel like I'm so close here, please can anyone give me any ideas? Thanks in advance!

Earlier Mac models

Posted on Jun 23, 2025 03:05 PM

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Answer 1

Jun 23, 2025 03:33 PM in response to Lexild

In Internet Recovery, you are running from a disk image called MacOS Base System which is pulled out of the Mac's ROM to run Recovery, Installer, Disk Utility. It creates about 30 RAM disks instead of putting ANYTHING on the boot drive, leaving the boot drive compeltey free for a deep repair.

if you can not repair the drive from Internet Recovery

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Answer 2

Jun 23, 2025 11:25 PM in response to Lexild

Is there anything important on the internal drive? If not, you are more free to experiment and try to erase it completely. Or get an external SSD and try to install macOS on it. Notice that if internal drive is broken, it could affect booting also from the external.

So try this either on the internal HDD (?) or the external SSD:

Reset PRAM: shutdown, power ON, when the Mac chimes start pressing Option-Command-P-R until it chimes four times, then let it finish booting. Does that fix the issue? If not:

Do a clean install on the internal or external disk via Internet Recovery: Disconnect ethernet cable and reboot the Wi-Fi router which should be nearby the Mac (might not be needed but at least in my setup Internet Recovery fails via ethernet for some reason), shutdown, power ON, when the Mac chimes start pressing Option-Command-R until you see a spinning globe, connect to Wi-Fi, and let the Mac boot to macOS setup screen (if it is High Sierra, it won't work without a workaround).

In macOS setup choose Disk Utility > View > Show All Devices, choose the topmost internal/external device (not any volumes under it), and erase either internal/external device as MacOS Extended Journaled, GUID, case insensitive (if it is a HDD) or APFS (if it is a SSD).

Then quit Disk Utility, and choose macOS install and install it to the internal or external disk. This might take about an hour or even more if the Wi-Fi is slow.

p.s. such old macOS might need a 3rd party browser like some older Firefox because the old Safari might not support new web pages.

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Answer 3

Jun 23, 2025 04:25 PM in response to Grant Bennet-Alder

... then the drive may not be any good any more,

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Dying(?) Mac Mini (7,1 _ late 2014) not recognising USB boot installer

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