I am seeking this info in order to advise others . . . I don't need to do it myself.
If you reset your M4 mini to its factory new condition, will it reinstall the macOS it shipped with or the latest?
Last year I read on these forums of somebody who seemed to have bricked their computer doing a factory reset.
What are the dangers?
Mac mini
Apparently it is a very real danger.
After posting I did a web search and received this information which was reinforced by numerous plaintive cries for help last year.
Apparently there were problems that occurred because of a bug in early versions of Sequoia which was eliminated in macOS 15.5 and later versions.
Dangers of resetting Mac mini M4 factory defaults using Apple's instructions:
✅ Recommendation: Always ensure your M4 Mac mini is updated to macOS 15.5 or later before using "Erase All Content and Settings." If you're preparing a Mac for resale, perform the reset only after confirming the latest OS update is installed.
Apparently it is a very real danger.
After posting I did a web search and received this information which was reinforced by numerous plaintive cries for help last year.
Apparently there were problems that occurred because of a bug in early versions of Sequoia which was eliminated in macOS 15.5 and later versions.
Dangers of resetting Mac mini M4 factory defaults using Apple's instructions:
✅ Recommendation: Always ensure your M4 Mac mini is updated to macOS 15.5 or later before using "Erase All Content and Settings." If you're preparing a Mac for resale, perform the reset only after confirming the latest OS update is installed.
To further expand upon @den.thed's reply......users with an M-series Mac must not erase the whole physical internal SSD, nor should they delete the hidden APFS Container or they will need to perform a DFU Firmware Restore. It has been a while, but deleting either the "Macintosh HD" or "Macintosh HD - Data" volumes may be a problem as well, especially both.....I'm not sure though. I'm not sure I have an M-series Mac I can experiment or the time.
If users follow Apple's latest instructions (for both Intel & M-series) to erase the "Macintosh HD" (or equivalent item), then Disk Utility will prompt the user to erase the Volume Group. If the user is not prompted to erase the "Volume Group", then they are performing the erase incorrectly. If they are asked to "delete" the Volume Group, then they are doing it wrong.
Only with the Intel Macs can a user erase the whole physical drive (it is my preferred method for an Intel Mac).
The "Erase All Content & Settings" is the best & quickest option for most people for the systems that allow it except for two specific cases:
Not all, but most of that Bricking was caused by using the old Disk Utility - Erase and Reinstall method.
For the properly method, see > Erase your Mac and reset it to factory settings - Apple Support
Basically only Erase All Contents and Settings.
It will go back to the macOS version I have currently installed and of cause the data you added to it, would be gone.
I'm sure apple do whatever they can to avoid people bricking their devices by factory reset, I can't say it never happened but never to me, nor to the wast majority of users I would bet.
Use Disk Utility to erase a Mac with Apple silicon - Apple Support says, "If you previously installed a macOS upgrade, you might be offered the macOS that you were using before you upgraded."
It does not say you have to use that version but I have not done this and Apple's statements are sometimes unclear when it uses terms like "might" (I have seen cases where "might" meant, "definitely will in 99.999% of cases).
If it came down to it, you could probably immediately downgrade if you used a bootable installer.
Thanks everyone for your contributions.
As shown from the quote above a number of people temporarily bricked their Macs using Apple's instructions because of a flaw in early versions of Sequoia.
I can remember some of the outbursts on these forums.
Anyway, it brings me to another probably connected point.
I run my M2 and M4 minis from external Thunderbolt NVMes and last Summer I booted back into my M4's SSD with no problem.
However, when I tried to boot back into the external I got the orange flashing light.
After an hour or so of panicking I managed to get it back into operation with help from tbirdvet who had experienced something similar.
Needless to say, I didn't switch out of the external drive again until last night when I realised (after reading the AI response) that my M4's SSD was running macOS 15.3.1 . . . one of the buggy versions.
So with my fingers crossed I booted into the internal Mac SSD and upgraded to 26.2 and (wait for it!) booted easily back into my external NVMe.
So was the orange light failure last year a fluke or caused by macOS 15.3.1? I will never know for sure but it looks highly likely that the buggy OS was probably to blame.
I hope the orange light issue was a one off case. It was scary to say the least. I have not run into this issue since and I keep making external boot drives and go back and forth between the internal and external. Also I never bricked my Mac when erasing the entire drive from recovery mode and reinstalling the OS like some have reported (maybe I'm just lucky).
I had only had the M4 for less than 3 months so wasn't too pleased!
The strange thing is that only days before someone had claimed to have an orange blinking light and I was rather dismissive of it . . . Karma?
After reading about early versions of Sequoia and subsequently upgrading the internal to Tahoe I feel more positive . . . touch wood!
Any dangers resetting M4 mini to factory defaults?
