MacPro5,1 Powering off


Over the past 1-2 months, my MacPro5,1 has, on about 6-8 occasions, powered itself off whilst I was not at the keyboard. Today alone it’s done it 3 times…

Whilst a power outage may have contributed once… mostly it’s just simply “happened” - when I’ve been away for some time (ie an hour+), I come back and find the computer has powered off.

The power cable is firmly seated at both the computer, and the outlet.

It is set to sleep after 1/2hr. I suspect it’s going to sleep and then shutting off for some reason.

My research suggests the power supply may be on the way out… although at least when that happened with my PMG5, it was happening much more frequently… til it didn’t turn on any more.

Is there anything else that I should check here…?



My 1st guess would be the power supply. Having said that, at least as far as I’m aware, the 5,1 power supplies are pretty robust. I ran mine with extra power to Radeon 570 & 580 vid cards for a year with no problem.

I don’t really know where else you could easily look…

Yes - that was my best guess…

I guess I’m just “confused” by the fact that I sit on the computer for 8 hours, 4 days a week (working from home Tue - Fri) and it hasn’t powered down once “in front of me” - and yet it’s suddenly started doing it when I’m not using it.

I’m keeping an eye out for a 2018 Mac Mini to replace the MacPro… may have to get a bit more serious in my search. I don’t think it’s going to be worthwhile replacing the power supply if it is dying…

Do what I did & get a second hand M1 Mac mini. There’s more & more of them on eBay now.

If I get an M1, I’d want to future proof by getting one with 16GB RAM… which currently asks a fair bit of money on eBay…

How much would you be looking at for a 2018 Mac mini?

I paid $1200 for my M1 mini including post with 16GB RAM & 512GB storage which I thought was pretty good.

Ideally I’d like to keep my next upgrade to around $800. I know I could get an i5 with 256GB (non upgradeable) SSD for that price… but the M1’s with 16GB RAM are much more like the $1200 you paid.

I was going to stay with the Intel option due to better multi monitor support… although in reality if/when my 23" Cinema displays die, I’ll probably be looking for a 24" Thunderbolt replacement, and the M1 could handle 2 of them.

We are house-hunting right now… feeling pretty ill about going $0.6m into debt… An extra $400 to get an M1 Mini with 16GB RAM shouldn’t really even be a blip on my radar lol.

I just checked the crash logs… can’t say 100%, but there’s been a number of “blued” crash reports for the past 2 days - that would roughly match the times the computer has gone down. Wondering if my Magic Trackpad may be causing the issue…

Oh - or… a new “locationd” crash report seems to suddenly being added every few seconds…!?

Is your Mac Pro pretty standard? What operating system are you on?

It’s the 2.8Ghz model, has a BluRay in the top optical bay (which disappears all the time) and an SSD in the bottom one. Otherwise entirely standard. Running Sierra.

Someone on MacRumors said to check the PRAM battery. Looking at a vid of where the battery sits - I don’t think I’ve ever changed it, so may well need replacing, and as noted - PRAM batteries can certainly cause strangeness on a Mac!

ps Talking of PRAM batteries - I found both my Pismo and TAM batteries last night whilst checking my “battery box”!

Interesting twist??

So - as per other thread, I have just set up an Icy Box, 4-bay hdd enclosure, and connected it to my Mac mini.

As noted, its fan is “noticeable”, though not loud. I’m not sure if it goes into a sleep mode if not used for a certain time… I know one of the boxes I was looking at does… so when I walked back in the office at some point, and it was silent, I thought - must be asleep.

Wake the mini, and get 3 x ‘disconnected drive’ warnings. Look at the IcyBox - and there’s no lights on it - it’s OFF.

So it shut itself off. The mini had not restarted / shut down. They are on the same power point, but the mini is connected to a 6 board, coming off the main 6 board that the Icy Box is connected to.

I’ll monitor it now, but am starting to wonder if the main 6 board has an issue. (Though - you’d think it would also have taken out the mini…)

Umm, having a six plug board plugged into another six plug board is certainly not ideal…

So this Icy Box you’ve got - is it just four separate drives? It hasn’t got some sort of hardware RAID built in?


Mac Mini
2 monitors
2 printers
Icy Box
Firewire box
Laptop charger
Battery charger

Not all are always on, or drawing current… could probably save a small fortune disconnecting a few of them unless needed… I think my office has a 2nd outlet, but it is covered by a huge wall cabinet. So they are all coming out of the 1 outlet. In fact - the 1 outlet has 2 sockets… the other socket is driving the Modem, POE, Cube and speakers…

The IcyBox does have some Raid features. Not sure exactly - I am not using them at the moment…

The only time I have ever had problems with a drive disconnecting it was the USB connection. I believe that is one reason they have now gone to the USB C plugs. Having said that, it doesn’t explain why the box would turn off…

Today I changed out the 6-board that I suspected was causing the MacPro5,1 and then the Icy Box JBOD to power down randomly.

The MacPro is now already in my son’s room, but the IcyBox - it had been powering down quite often since I got it last week. We’re now at almost 12 hours since I changed the board, and it’s been running without fault.

I don’t think it has a sleep function, so when I get up in the morning I’ll be expecting it to still be purring away.

Moments you are glad you were wearing thongs… When you’re down on your knees about to crawl under a desk after moving a box that’s been sitting there for a good few years… and you see a black bulbous spider crawling toward you… SPLAT.

And this morning the IcyBox has turned itself off… MacMini plugged into the same 6-board was in sleep mode - woke up with a click on the keyboard.

That’s a problem. Don’t really know what to suggest…

I’ll have to set it up in another room and see if it still powers off… and check the specs but I’m sure it shouldn’t just turn off in its own. It lasted 4 hrs ok on Sunday whilst read/writing between drives.

Just thinking about it, must be some sort of power issue whether that’s inside or out of the box.

I just - wait for it - read the instructions!

It’s actually one of the IcyBox’s features called “Sync”. It can detect if the PC that it’s connected to is “on” or “off”, and adjust accordingly. In this case, the default was to power off if the PC was “off”. (In this case - the Mac Mini going to sleep.) I did a test, and sure enough 15 seconds after putting the Mini to sleep, the IcyBox shut itself down.

I have changed it to instead go into “hibernate” mode. Will run a few tests - need to know that it will wake back up when the Mini wakes.

It can also stay always on.

Also - I think I said this box can do RAID - It can’t. The instructions are for 2 different models, and mine is a non-Raid box. Not sure how much more for the RAID options, but that’s no problem for me.

Amazing what happens when you jump to conclusions. :slight_smile:

Although - that means the MacPro was likely indeed shutting itself down…

You can always set up RAID in Disk Utility if you need to…