Updating macOS resulted in damaged Firmware. Does that mean the hardware is ok?

[katewes]

When I last updated macOS to 11.4, it bricked my Mac Mini M1.

Because of lockdowns in place then, instead of taking it to an Apple Store, it was repaired by a nearby authorised Apple dealer - who said the firmware had been damaged by the macOS update. So they replaced the firmware, and it now runs normally using 11.5.2.

I wonder, however, whether there was something amiss with the hardware that resulted in the macOS update leading to the Firmware failure? Should I get the Mac re-tested by Apple? Should I demand a replacement unit?

(I'm a little queasy to update to 11.6 given what happened last time).

 

[Realityck]

When I last updated macOS to 11.4, it bricked my Mac Mini M1.

Because of lockdowns in place then, instead of taking it to an Apple Store, it was repaired by a nearby authorised Apple dealer - who said the firmware had been damaged by the macOS update. So they replaced the firmware, and it now runs normally using 11.5.2.

I wonder, however, whether there was something amiss with the hardware that resulted in the macOS update leading to the Firmware failure? Should I get the Mac re-tested by Apple? Should I demand a replacement unit?

(I'm a little queasy to update to 11.6 given what happened last time).

Just schedule a genius appointment.
Then go to a Apple store and they will do a DFU (M1 Mac to M1 laptop using a USB-C to USB-C cable) and this will revive everything back to working order. If you have it recently backed up to other storage, then they could also do a restore of everything to the current 11.6 which is newer than what you updated to. Sometimes odd things happen its not like you really have to worry.

 

[mr_roboto]

Short answer: Make a backup, then do it. You want the security update contained in 11.6.


Long answer: You need to understand what actually forced you to bring the Mac in for service.

M1 chips have two levels of firmware. One is stored in mask ROM, part of the M1 chip itself. This is the firmware which runs when you first power the computer on. It's truly read-only; software cannot erase or write to it. If there's a problem with it, you need a new motherboard, end of story.

That first level's job is to load the second-stage firmware image from a read/erase/write flash chip on the motherboard. Apple OS updates frequently update the contents of that flash memory as well as installing new software versions on your SSD. That firmware flash update is what failed and bricked your M1 Mini once before.

There are many ways this can happen without it being a sign of bad hardware. The updater software can be buggy. Power can fail or glitch. Such events leave you with a physically OK firmware flash chip whose contents are corrupted to the point that the computer cannot boot.

I can just about guarantee that all the dealer did was the process @Realityck mentions. In most cases, if you're technically minded and have a second Mac to run Apple Configurator 2 on, you can do it yourself.

In sum, it's unlikely anything was ever physically wrong with your computer. On the outside chance that there was, you should make a point of keeping up with every last minor macOS update while the warranty is still active. You want it to fail again while it's still covered so you can ask for a replacement. Just follow the practice of making a backup before every update, which is good to do anyways.