The other day I was doing simple edits to a photo using Preview app on my Mac, to my surprise the machine first froze for a few seconds and shut down itself.
More surprisingly it restarted (I swear I didn’t press the start button). I’m on an old Mac ? precisely, a 2012 model MacBook Pro.
A quick research turns out that I was not the only “casualty”, and it seems the causes are still kind of unknown. Some said they managed to fix the problem by replacing the motherboard, some said you should go change the battery.
Well, I did suspect that it was related to the battery issue, as it always says “replace soon” while checking the battery condition.
But, it’s still hard to pinpoint the real “culprit”, after spending hours looking into scores of Apple macOS threads in different communities/forums.
Although many fellow Mac users even called Apple support team and did send their Mac machines to Genius Bar for diagnosis, turned out Apple genius guys weren’t that helpful — and the experiences frustrated many of us which is reasonable considering the time and efforts they invested.
SMC Reset Seems The Obvious Solution
The only official guide is from this Apple article, whether it indicates some symptoms that might mean an SMC reset is necessary:
Your Mac sleeps or shuts down unexpectedly and you can’t turn it back on.
Here’s a nice video showing you how to reset it:
But, I’m Not Sure Whether It’ll Work Out
I’ve already tried that, but it would take some time for me to conclude that a SMC reset is the working solution.
Are You Using an iMac?
In this iFixit thread, Billy Moon shared his story about random shutdown (he’s using an?iMac 27″ 3.4 GHz i7, Late 2012) and he managed to fix the issue by replacing the power supply. After five months, the issue never comes back again.
This is one of the few cases I’ve seen people resolving the problem. So, if you’re on an old iMac (instead of MacBook Pro), that solution might work for you too. Thanks Billy and “Mayer” for the great discussion!
Or if you have good suggestions or experiences regarding this kind of weird mac shutting down issue, leave a comment and let me know.