Mac Mini crashing on sleep

Yes. And it is even not BootROM itself, as SU 2020-002 did not change my Mac mini BootROM version. But it is certainly some firmware piece as after applying of SU 2020-002 my Mac mini shows this issue with clean install of High Sierra (and even El Capitan) with a blank drive.

It is indeed the T2 chip in my experience. This -20 cause happens with my iMac Pro and there is a kernel panic caused by BridgeOS, the system shuts down and starts up again with the error log to Apple message. It's been going on for many months and I've basically given up on doing anything long running on that machine. Just restart it every morning and it will keep running. Let it run for a few days and it will crash while it is sleeping usually. I was too stupid to understand what was going on until it was out of warranty. There is nothing plugged in to the iMac Pro, I even unplugged the Time Machine drive.

I ran memtest86 on my first pair of 16gb x 2 of OWC ram which caused it to crash. However, the new ram passed with flying colors. I'm still having the possible "T2/usb/bluetooth/wifi" errors, crashes about once or twice a day. Sucks too because I have to unplug the power otherwise the power button will not restart the machine.

Yep, this is what I was talking about. I had to increase memory to 32GB to make my Mac Mini works without crash. Ridiculous.

1. Memory issues – Reports of large increases of memory usage = no free memory and a large amount of compressed memory.

It works!

I updated a sacrificial drive to Big Sur over the weekend and whatever firmware it installed did the trick.

I can now use my normal Mojave boot drive without any crash reports for the first time since SecUpdate 2020-002 in March.

And the startup chime is back too!

I was having this issue but the latest security update (along with a Safari update) seems to have fixed it.

I have the same issue except no eGPU. I have tried removing all kernel extensions. It might be Chrome related. I reset SMC and ran hardware test. All shows up as good. I was planning to do PRAM next, but I think removing Google auto-update stuff via LaunchControl (an essential utility IMHO, esp if removing spyware) and making sure Chrome is not running during sleep may fix it. I will keep trying but so far that seems to work... but I also removed traces of VMWare, Malwarebytes, Vallum, and some other stuff.

If you really want to have fun, there's always a clean install to a fresh disk and test with only the default installation. Then slowly add back applications a few at a time until you find the culprit.

Also, I'm sure you've probably already done this but have you tried starting up in Safe Mode and testing?

I sent the following message to https://www.apple.com/feedback/macos.html Please do the same to get Apple's attention.

"Previously a very stable Mac mini 2018 has now started to crash after going to sleep. Also after a cold boot there is a crash report. This started to happen after Security Update 2020-002 (Mojave). Resetting SMC or PRAM or safe-boot or checking with Disk First Aid does not help."

I replied earlier but not specifically to you. I _think_ I have it. It was either some old software or, since I had the problem even in Safe boot, an SMC reset.

I thought I'd reset the SMC earlier but it gives no indication of success and my freakin’ Apple Watch shuts off before 15 seconds are up so counting the seconds isn't foolproof... and it's quite possible I screwed up the first attempt at an SMC reset.

It's back. I was wrong to think it had gone away! In one case it took all of 15 seconds.

Thinking Safari might be part of it.

sudo log show --predicate 'eventMessage contains "Previous shutdown cause"' --last 24h

Timestamp Thread Type Activity PID TTL

2020-04-01 14:04:08.231152-0400 0xc3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 5

2020-04-01 14:19:59.023773-0400 0xc3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: -20

2020-04-01 15:11:36.178824-0400 0xc3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 1

2020-04-01 16:30:14.996965-0400 0xc3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 1

2020-04-01 16:36:56.616467-0400 0xc3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 1

2020-04-01 16:55:01.152086-0400 0xc3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: -20

2020-04-01 17:14:04.048306-0400 0xc3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 0

2020-04-02 12:19:04.003310-0400 0xc3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 5

2020-04-02 13:28:35.397731-0400 0xc3 Default 0x0 0 0 kernel: (AppleSMC) Previous shutdown cause: 5

Thanks for the update. I haven't tried it yet, but if it is sleep related, couldn't energy saver be configured to sleep the screen but not the mini? It would be a work around until Apple's next patch.

In energy saving preferences, I checked don't put Mac to sleep when display sleeps. I still got the same crash as when it was not checked.

Davert-it seems like you tried everything. I assume you have a monitor and external drive connected. Have you tried with no external drive and assuming you are using USB C, connecting your monitor to a different port (not next to one it is currently plugged in to)? I recall reading some Macbook Pros had an issue with a specific port after update a few years ago.

Also, could you run Catalina on the internal and install Mojave on your Samsung. You could then boot to whichever you wanted depending upon your needs (windows, Catalina, Mojave)?

Thanks again your your trouble shooting.

Same problem here. I suspected the update so I reverted back with Time Machine. It still crashes.

Thought it might be the eGPU through Thunderbolt so I switched to direct HDMI. Still crashes on sleep or boot.

I tried SMC & PRAM. No change.

Thanks to everyone who did the troubleshooting in this thread.

Looks like it's firmware, so I'll go back to waiting for Apple to get off it's humongous butt and fix it.