MacPro (2012) will not go to sleep automatically or manually

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MacPro (2012) will not go to sleep automatically or manually

I have a trusty ancient MacPro – the big heavy box, not the laptop (2012 – Mojave; 10.14.6) which serves well for what I need from it. However, for several years now, it would not go to sleep when idle for a specified time. Yes, I did go to System Preferences to specify when it should automatically go to sleep. Occasionally I would change the time before automatically going to sleep, depending on what work I was doing. Early on, the MacPro did just what i wanted...automatically.

Maybe three years ago, it stopped doing that. That was disappointing, but I could solve it simply by using the apple Menu to direct the Mac to sleep.

These days, it doesn't always go to sleep when I manually reach for the Apple menu to sleep the Mac....today for example. And yesterday too.

I have begun to theorize that after not being shut down for a few weeks, the automatic function is somehow corrupted, and unable to let the machine sleep. At those times, I do a full shut down and leave the machine for a few hours or overnight. In the recent past, when i've done that, I can then successfully put the Mac to sleep via the Apple menu as i've often done.

But NOT yesterday. And NOT today. The Mac was shut down overnight. This morning when I started it back up, it WOULD NOT go to sleep when I attempted to use the Apple menu to sleep the machine.

In other words, my Mac is either running and doing what I'm asking, or it's powered down completely...With no middle ground.

Why is this happening? is there anything I can do to "fix" this problem?

Thanks for any advice, this is way above my pay grade.

Mac Pro, macOS 10.14

Posted on Jun 8, 2026 10:26 PM

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Answer 1

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Allan Jones

Level 10

82,796 points

Jun 9, 2026 8:00 AM in response to tytoalbaow

Good morning.

I would first try an SMC reset: Reset the SMC of your Mac - Apple Support . Be sure to use the proper instruction set for an Intel Mac without the T2 security chip.

If that has no effect, then I would go with a Safe Mode boot: Start up your Mac in safe mode - Apple Support. I let my Macs "soak" for 20-30 minutes in Safe Mode before restarting normally. That gives Safe Mode time to complete its housekeeping chores.

Neither an SMC reset not Safe Mode should introduce new issues, and they cost noting to perform.

If you have loaded up your Mac Pro with a bunch of useless anti-virus apps, "cleaning" apps, or VPNs, those could cause your issues.

If these suggestions don't help, we may need to see a system config report. That can be done safely, but we'll cover that if the SMC reset and Safe Mode don't help.

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