ChrisR
My #Apple 16" M1 #MacBookPro has just rebooted itself... again. It was fully charged; I closed the lid and left it for a few minutes to get a cup of tea. When I came back it re-booted. It's happened a few times recently. Running Sonoma 14.8.5. Anyone have any ideas what could be happening? Running #BitDefender which seems happy...
Jun 15 at 6:57amWeb
Show threadSuzy RichardsJun 15

@carusb It should keep logs somewhere of why it's doing it.

Are auto updates on? I'd turn those off to see if that changes how it behaves.

If there hardware tests to run I'd try those. Could have a faulty memory chip. That can cause havoc.

Show threadChrisRJun 15
@serichards Auto updates off, which is how I've managed to stay on Sonoma... No idea where any logs might be, or how to run hardware tests. (Under System Information, Diagnostics says No information Found). Full BitDefender scan, nothing found.
Show threadSuzy RichardsJun 15

@carusb Think I used the D option on start up to run diagnostics before.

https://support.apple.com/en-us/102550

Also worth ruling out dust and over heating. Have you got a blower thing you could blow through the vents with while it is turned off?

Use Apple Diagnostics to test your Mac - Apple Support

Apple Diagnostics, formerly known as Apple Hardware Test, can check your Mac for hardware issues.

Apple Support
Show threadKaiser   📷 🎞️ 💿 Jun 15

@carusb There’s an app called Onyx (free) that has a suite of diagnostic and maintenance scripts, might be worth downloading and installing and running some of the checks it has available?

https://www.titanium-software.fr/en/onyx.html

Titanium Software | Operating System Utilities for Mac - OnyX

OnyX is a multifunction utility that you can use to verify the startup disk and the structure of its system files, perform cleaning and computer maintenance tasks, uninstall applications, configure some hidden parameters of many Apple applications, and more.

Show threadTheriacJun 15
@carusb
a kernel panic perhaps?
Show threadEstarriol, Terrorist DragonJun 15

@carusb

first, back up anything important.

likely culprits are:

MAC OS overriding the auto updates off

Overheating power supply/ system chip

Hard disk issues

Memory/other chips playing up

My money is 1, then 2.

Show threadDeixis9Jun 15

@carusb Mine has been doing that since the guarantee ran out circa 2021; if it isn't touched for a few minutes it reboots. This began at the same time the touch bar began strobing.

Still going though. Updates seem to affect the M1, untested I guess

There's a thread on the Mac forum.

Let me know if there's ever a class lawsuit.

#M1MacBook

Show threadChrisRJun 16

@Deixis9 @Thebratdragon
@Theriac
@kaiser_franz
@serichards Happened again this morning. Done a full BitDefender scan, all fine. Did a restart and ran Apple Diagnostics, all fine. Still on 14.8.5, so auto-update's not on. Spotted a couple of apps that had updated themselves more recently, decided I didn't need them (BBEdit??), gone

A possible common link is using the laptop sitting up in bed in the morning, so it's resting on the duvet, then closed and laid on the duvet. So, temperature? 1/2

Show threadChrisRJun 16

@Deixis9 @Thebratdragon @Theriac @kaiser_franz @serichards I thought there was a temperature measure in Activity Monitor, but it's Energy. Highest usage by far last 12 hours was Dropbox. Had a close look & found some files in a folder for my sister that had little clouds against them. I suspect it's been struggling to sync them for ~10 years! Deleted them, and Dropbox Energy usage has dropped through the floor.

Used my rocket blower on the vents (?), wondered if I should try vacuuming them? 2/2

Show threadSuzy RichardsJun 16
@carusb @Deixis9 @Thebratdragon @Theriac @kaiser_franz Definitely worth a hoover.
Show threadEstarriol, Terrorist DragonJun 16

@carusb @Deixis9 @Theriac @kaiser_franz @serichards

get a sheet of chipboard or similar, the size of the laptop and rest iy on that, see if hat helps.

Show threadChrisRJun 17
@Thebratdragon Currently sitting on a book, which ISTR is what I used to do (my old 2014 MBP had vents underneath, I think, while this one is solid metal, which is maybe why I relaxed that precaution!).
Show threadEstarriol, Terrorist DragonJun 17

@carusb

being solid metal might be part of its heat dissipation method.

Can you leave it running up on 2 runners so most of the base has airflow and see if it plays up then?

Show threadKaiser   📷 🎞️ 💿 Jun 16

@carusb @Deixis9 @Thebratdragon @Theriac @serichards

A few more things you can try based on my limited research:

In a terminal run:

log show --predicate 'eventMessage contains "Previous shutdown cause"' --last 30d

Apparently a code of -3 means thermal shutdown

You can also run:

ls /Library/Logs/DiagnosticReports/

If any files it returns are .panic then it was a hard crash and you can view those files to maybe get some more info?