Unexpected Shut Down Question

Hello, I have a 2018 Mac Mini that shut itself off unexpectedly when I was away from my house. Usually my computer will sleep when I am away for a period of time. After a little bit of googling, I found a terminal command to list causes of shut downs. After using this command, I saw that the cause was “-3” so I went back to google to look for what this means. If I understand correctly, this means that a temperature sensor was high.

My question is if this is a cause for concern? Are there things I can do to check the health of my system? My usage is fairly low key, general web browsing, media consumption, and some light office work like word processing and spreadsheets for things at home. I’m surprised if these kind of tasks are putting excessive thermal pressure on the system. Are there things I should be checking?

Thank you to anyone who took the time to read.

Based on this iFixit guide, it suggests running a hardware diagnostic test (replacement for Apple Hardware Test).

I haven’t done this before but it would be a good start to check and see if anything is reported.

You might also want to try cleaning out the fans with some compressed air. If there’s a lot of dust, it can have a big impact on the cooling system’s ability to keep the components in check.

1 Like

First of all, here is the official Guide, how Apple allows the cleaning of its devices.

This should be read, and understand, before you start cleaning.

After you understand this guideline, and if you know how to use a Screwdriver, here is a description from iFixit, how to replace the Fan. This guide shows, how to open it, so you could clean from the inside, if necessary.

I would, in general, not recommend to use compressed Air to blow into any kind of device, as you have good chances, to either destroy some fragile structures in the worst case, or at least to spread all the dust inside the whole case, and not only on the Fan and the cover, and produce this way a was larger problem, as you had before. There is normally no way to remove Dust, by simply blowing inside a Device.
A light relive could also be a special VacCleaner for Electronics.

Also I started my 2017iMac every 4th Day completely new, to get small failures deleted by the system start again, which improves significantly the reliability and performance of my old iMac.

1 Like

You could also try the iStat Menus app which I keep running all the time on my Mac or the TG Pro app which I’ve heard good things about.


Yeah, I knew that someone wouldn’t understand sarcasms here… :thinking: :wink: :rofl: :joy: :rofl: :champagne:

1 Like

Thank you to everyone who suggested things to me! Nothing was detected with the Apple Diagnostics tests, but I will continue to monitor and if issues persist, I might open things up and take a look inside. Thanks again!