Hello,
I have a problem with this feature on my M2 Mac Mini. I tried everything I could (removing the power cable after enabling the feature then re-plus the cable, enabling the feature then restart and removing the power cable and re-plug) but it doesn't work as expected most of the time (so yes, it work on rare occasions). What can I do to fix it?
Thanks
[Re-Titled by Moderator]
Mac mini (M2, 2023)
I am aware that too many attempts to power on via the cable could damage the Mac, thanks for reminding this, so I used to wait a few moments to allow the capacitors to discharge. However, I need to ensure that powering it back on will allow the Mac to start after a power outage as expected, but it doesn't. I have another Mac Mini M2 that is strictly identical, with the “Start Up Automatically After a Power Failure” setting enabled, and it works as expected. The only difference between the two M2 Macs is that it uses Sequoia 15.1, whereas the problematic Mac Mini is on 15.2. Could this be related to the new version of Sequoia?
If you believe there is a Software “ Bug “ in Sequoia 15.2
Stop testing on your equipment and Report your findings to Apple. Be sure to use the " Bug Report " In the Feedback Type category
Let them Test this on their equipment. After all, they have deep pockets to replace borked or otherwise damaged Apple Computers
In my own setup with a former M1 Mac Mini, current M2 Mac Mini and current M4 Mac Mini.
Each machine & accompanying Monitors, Printers / Scanners are each attached to a separate APC / UPS that guards against power broken-outs, power spikes and / or power outages
Each UPS can run for about 90 minutes during a prolonged power outage.
Giving me plenty of time to shutdown all equipment in a control environment
Unless the user has addition money to purchase a new machine
I would stop attempting to duplicate a Real Power Failure
Doing what the user is currently doing.
May, over time cause a Hardware failure which can not be repaired by normal in-home methods
If it has worked " so yes, it work on rare occasions) "
It may have been because you unplugged to Apple Silicon computer just long enough for it to have done the equivalent of a SMC Reset on an Apple Intel Computer
If you have Mac with Apple silicon
Make sure that your Mac is plugged into power, then take one of these actions.
No other steps are necessary for Mac computers with Apple silicon
This Mac mini is embedded in a 19" rack exclusively for doing some audio tasks and must be considered as an audio processor, so the power switch is not accessible to the end user and none APC / UPS install would solve my case.
I tried different things like downgrading to Sonoma but no changes, so it doesn't seems related to Sequoia.
Then I noticed that if I set 'Set time and date automatically' to OFF, the date is going back to 31 December 1969 after some minutes with the power cable removed. The internal battery was changed but it doesn't solved the problem. Then I moved back 'Set time and date automatically' to ON because there was no internet access (and probably many other things) with the 1969 date. Then I proceed to some hardware diagnostics but nothing was found.
If I tried to enable 'Start up automatically after a power failure' from Terminal instead of Setting / Energy I get the following error :
sudo systemsetup -setrestartpowerfailure on
Password:
2024-12-16 22:58:53.214 systemsetup[744:8420] ### Error:-99 File:/AppleInternal/Library/BuildRoots/b11baf73-9ee0-11ef-b7b4-7aebe1f78c73/Library/Caches/com.apple.xbs/Sources/Admin/InternetServices.m Line:379
setrestartpowerfailure: On
support@Supports-Mac-mini ~ %
MacOS 'Start up automatically after a power failure' issue on Sequoia 15.2
