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UKenGB

macrumors regular
Original poster
Feb 21, 2010
168
42
Surrey, UK
My Mac Pro is a 4,1 => 5,1 and has been running Mojave almost perfectly for over a year. But…

A couple of days ago, when I tried to wake it up in the morning, I found it was actually completely off. I started it up and it ran perfectly and that evening sent it to sleep. But the following morning it was again off.

I ascertained there had been no power problems over either night and that next evening discovered that when I sent it to sleep, it simply shutdown immediately. In other words, it acted as if the command had been to shutdown instead of sleep. It was now unable to sleep and always shutdown instead.

I reset the SMC and also the NVRAM (which caused other issues now resolved), but despite numerous deliberate (and clean) restarts, it is still unable to simply sleep. I have previously had issues with it not staying asleep, but that was always down to an assertion held by some software I hadn't realised was still running. But this is the opposite. It won't just sleep and goes straight to power off state.

Looking at the pmset logs, each time this occurs, it tries to sleep, but there's an entry about preventing sleep and then when re-started, it logs a Failure to sleep. So there is something that seems to be getting in the way of simply sleeping, but I've no idea what that is. Here's that portion of the pmset log:-

Code:
2020-01-16 14:03:13 +0000 Notification            Display is turned off                                                                   
2020-01-16 14:03:13 +0000 Assertions              PID 103(hidd) Summary UserIsActive "com.apple.iohideventsystem.queue.tickle.4294968973.17" 00:00:00  id:0x0x90000809b [System: DeclUser kDisp]         
2020-01-16 14:03:13 +0000 Assertions              Kernel Idle sleep preventers: -None-         
2020-01-16 14:03:13 +0000 Assertions              PID 62(powerd) Created InternalPreventSleep "com.apple.powermanagement.darkwakelinger" 00:00:00  id:0x0xd00008477 [System: PrevIdle DeclUser SRPrevSleep kCPU kDisp]         
2020-01-16 14:11:07 +0000 HibernateStats          hibmode=0 standbydelay=0                                                                 0             
Sleep/Wakes since boot at 2020-01-16 13:05:21 +0000 :0   Dark Wake Count in this sleep cycle:1

Time stamp                Domain                  Message                                                                        Duration      Delay     
==========                ======                  =======                                                                        ========      =====     
UUID: Unknown UUID
2020-01-16 14:11:07 +0000 Failure                 Sleep Failure [code:0xFFFFFFFF0000001F]:                                                 
Sleep/Wakes since boot at 2020-01-16 13:05:21 +0000 :0   Dark Wake Count in this sleep cycle:1

Time stamp                Domain                  Message                                                                        Duration      Delay     
==========                ======                  =======                                                                        ========      =====     
UUID: (null)
2020-01-16 14:11:07 +0000 Start                   powerd process is started                                                               
2020-01-16 14:11:07 +0000 Assertions              Summary- [System: No Assertions] Using AC         
2020-01-16 14:11:09 +0000 Assertions              Kernel Idle sleep preventers: IODisplayWrangler

If I deliberately restart, there is no 'InternalPreventSleep' entry and 'Failure' logged after it starts up again. In fact it is powerd doing this, but why and is it actually the cause of it skipping Sleep and going straight to Shutdown?

I can confirm there has been no change to this Mac's configuration for a long time. It is used, sent to sleep overnight and woken up the next morning for use. Nothing has been changed for months, but 3 days ago it simply decided to misbehave in this way.

Anyone shed any light on this?
 

Snow Tiger

macrumors 6502a
Dec 18, 2019
854
634
What OS are you using ? There are sleep problems with many of these upgraded Macs . Try to upgrade to the latest version of your macOS .
 

UKenGB

macrumors regular
Original poster
Feb 21, 2010
168
42
Surrey, UK
Well it's 10.14.6, but it's been on Mojave for over a year and the latest update was some time ago. However this problem only (spontaneously) surfaced 4 days ago, so I doubt it's anything specifically to do with the OS version.
 

Snow Tiger

macrumors 6502a
Dec 18, 2019
854
634
Well it's 10.14.6, but it's been on Mojave for over a year and the latest update was some time ago. However this problem only (spontaneously) surfaced 4 days ago, so I doubt it's anything specifically to do with the OS version.

Have you added any new components to your Mac lately , internally or externally ? I once had a client attach an USB hub to his Mac that caused serious instability issues when it electronically "pinged" his Mac at regular intervals .

If its been over a year , you might just want to perform a clean reinstall of the macOS and see if that helps .
 

geo88

macrumors member
Nov 19, 2019
53
26
Nashville, USA
Hmm...one other thing comes to mind. I seem to recall another report of the error [code:0xFFFFFFFF0000001F] being related to Wake On LAN problems. If nothing else on the network has changed, perhaps there is a .plist somewhere that became corrupt.
 

Snow Tiger

macrumors 6502a
Dec 18, 2019
854
634
Hmm...one other thing comes to mind. I seem to recall another report of the error [code:0xFFFFFFFF0000001F] being related to Wake On LAN problems. If nothing else on the network has changed, perhaps there is a .plist somewhere that became corrupt.

Then there is the good practice of doing a clean install of the macOS of your boot drive once a year . It works wonders with dealing with all those troublesome corrupt files , excess files and over all inefficient file system .

And of course , if this is a production Mac , having a ready made CCC backup image of your boot device with a nice clean install of your macOS , your favorite apps and the necessary user preference settings for everything is even nicer . What might be a three day job from scratch will more likely just be three hours instead .
 
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UKenGB

macrumors regular
Original poster
Feb 21, 2010
168
42
Surrey, UK
Hmm...one other thing comes to mind. I seem to recall another report of the error [code:0xFFFFFFFF0000001F] being related to Wake On LAN problems. If nothing else on the network has changed, perhaps there is a .plist somewhere that became corrupt.

Wake On Lan has never been turned on and is not now on. Nothing likely to cause problems there I would think.
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Then there is the good practice of doing a clean install of the macOS of your boot drive once a year . It works wonders with dealing with all those troublesome corrupt files , excess files and over all inefficient file system .

And of course , if this is a production Mac , having a ready made CCC backup image of your boot device with a nice clean install of your macOS , your favorite apps and the necessary user preference settings for everything is even nicer . What might be a three day job from scratch will more likely just be three hours instead .

I'm trying to avoid a clean install as it takes so long to get back to where you were and maybe won't help anyway. However, I may just have to try that.

In any case, I want to install some faster CPUs and then get Catalina on here, but I really wanted to start that from a position of it all running correctly - which it was until about a week ago. So ideally I want to isolate the actual cause of this, fix it and then start the update process.

It's as if there is a setting somewhere for 'Translate all Sleep commands into Shutdown'. No matter which way I try it, telling it to go to sleep makes it nicely shut down instead.

I do have a backup clone from before this started. I'll boot from that and see if it's the same. It'll take some time as mechanical Hard Disks are so slow these days. :(
 
Last edited:

MIKX

macrumors 68000
Dec 16, 2004
1,815
691
Japan
UKenGB

You could do a clean install to a separate SSD/HDD drive.

Clean, full installs without 3rd. party apps installed is a very good way to find out what's happening.
 

UKenGB

macrumors regular
Original poster
Feb 21, 2010
168
42
Surrey, UK
And the solution is...

Replacement PSU.

A while after starting this thread, there was a main power failure, but once corrected, this Mac Pro would not start at all so put it to one side and used a Mini I had available.

I had read somewhere that a failing PSU had caused similar problems and eventually managed to obtain a good one from a working machine. But in the meantime, I discovered that having been disconnected for some time, the Mac Pro would now boot again, although sleep problem remained and I noticed that a few seconds after going to sleep, it would simply stop and one of the red internal warning LEDs would light up for a while. CPU over temperature warning?

So I was not hopeful about this being simply a PSU issue, however after a couple of months I figured I had to try swapping the PSU just to see if it worked. Surprise, surprise, with the replacement PSU it started perfectly, went to sleep when it should, either by timeout or manual command and always woke up and no warning LEDs.

Only been a few days, but since with the original PSU this was a 100% problem and now 0% with the replacement PSU, I am now sure that the entire problem was some sort of failure of the original PSU. I might see if I can get it fixed somewhere.

So, hope others with similar symptoms might find this useful.
 
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