Niku
Level 2 (306 points)
Mac OS X

Q: How can I stop my iMac from automatically shutting down?

It happened again: I went to bed after waiting several hours for an operation to be completed, but when I woke up, the computer was off, and the job will have to be started again from the beginning. Now, maybe somethings's wrong. Maybe the computer shut itself off in self-protection. I started indexing my hard drive around 2:15 PM and I went to bed at 11:35 PM. At that time, 48,000 files had been scanned, and 46,692 files had been "handled," whatever that means. Also of interest is the fact that the total remained the same almost from the beginning. I know because I checked every fifteen, sometimes thirty, minutes, or so. These automatic shutdowns happen all the time, but they were just an annoyance before. However, something like this is a major problem.

OS X Yosemite (10.10.2)

Posted on May 10, 2015 6:56 AM

by Topher Kessler,Solvedanswer
Topher Kessler Topher Kessler
Level 6 (9,866 points)
A:

Its not expected at all, and indicates a hardware malfunction that will need to be addressed. Your Mac should stay on as long as you want, provided constant power is supplied to it.

Posted on May 10, 2015 10:46 PM

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Niku

Q: How can I stop my iMac from automatically shutting down?

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  • by Barney-15E,

    Barney-15E Barney-15E May 10, 2015 7:18 AM in response to Niku
    Level 9 (50,793 points)
    Mac OS X
    May 10, 2015 7:18 AM in response to Niku

    Open Console app and show the contents of the System Diagnostic Reports section by clicking on the disclosure trangle next to that name in the Log List.

    Look for a report that starts with Kernel and ends with .panic. There will be a time stamp inbetween. If one of those exists, please post the most recent.

    Just copy the text from the console window and paste it in here.

  • by Niku,

    Niku Niku May 10, 2015 7:47 AM in response to Barney-15E
    Level 2 (306 points)
    Mac OS X
    May 10, 2015 7:47 AM in response to Barney-15E

    It's not there. I checked very carefully, but it's just not there

  • by Topher Kessler,

    Topher Kessler Topher Kessler May 10, 2015 8:21 AM in response to Niku
    Level 6 (9,866 points)
    May 10, 2015 8:21 AM in response to Niku

    Try plugging your system into another power source, or see if you can get a UPS (battery backup) for providing a stable power flow. Then if the system continues to shut off, you likely have a faulty power supply in your system and will need to have it serviced.

  • by Allan Jones,

    Allan Jones Allan Jones May 10, 2015 8:35 AM in response to Niku
    Level 8 (35,316 points)
    iPad
    May 10, 2015 8:35 AM in response to Niku
    Maybe the computer shut itself off in self-protection.

     

    That could well be the case. Your computer has thermal protection. If some component approaches temperature that could damage a monitored piece of hardware, the computer shuts down out of a sense of self-preservation. The critical temp for most components is about 100C/212F.

     

    Your iMac may have a lot of dust blocking the air intakes on the bottom edge of the case, and inside the RAM access plate, should you model iMac have one. Starting in 2012, 21.5-inch model lost the access doe and it was moved away from the bottom air intakes on the 27-inch models.

     

    Inspect the air intakes for dust and remove with a vacuum cleaner, taking care not to touch the case with the nozzle or attachment. Use a static-free brush (wood handle and natural, not synthetic bristle--I use a pastry brush) to dislodge stubborn deposits . If your computer has a RAM access plate, remove it also. The RAM compartment likes to attract dust. Remove any dust from the RAM compartment with a brush.

     

    Once done with that, reinstall the RAM access panel (if applicable) and then look at you workstation. Make certain nothing is stacked under the computer. It doesn't take a lot of stuff under the computer to disrupt airflow. Now make sure the exhaust vent to insure nothing obstructs it. IT should be no less than 6 inches (~150mm) from any upright portion of your workstation. On my Mid 2010 iMac, the exhaust slot is about 1/2 inch (13mm) from the top of the case. I don't know exact where it is on a late 2012 or newer model--I've never had the chance to examine one.

     

    If yo u found a lot of dust and it has been removed, try the long task again. It pays to monitor temperatures. Macs that are mid-2012 and older can use this program:

     

    http://www.bresink.com/osx/HardwareMonitor.html

     

    Also see this Apple article that addresses overheating and its causes:

     

    Apps can affect Mac performance, battery runtime, temperature, and fan activity - Apple Support

     

    If you are running any third-party anti-virus apps of so-called "cleaning/optimization/tune-up" software, those can run up temps and should be removed.

  • by iW00,

    iW00 iW00 May 10, 2015 8:37 AM in response to Niku
    Level 4 (1,349 points)
    May 10, 2015 8:37 AM in response to Niku

    Start with simple steps: go to System Preferences > Energy Saver, click on Schedule button and make sure you do not have scheduled your Mac to turn itself off at some specific hour.

  • by Niku,Helpful

    Niku Niku May 10, 2015 9:04 AM in response to iW00
    Level 2 (306 points)
    Mac OS X
    May 10, 2015 9:04 AM in response to iW00

    I think you might be on to something. I returned to Energy Saver, but this time I gained a better understanding of its settings. I selected "NEVER". Hopefully, this simple adjustment will put an end to the problems I have been having. I can't yet award you with a SOLVED award, but you have certainly helped--I think. Thanks a lot.

  • by Niku,

    Niku Niku May 10, 2015 9:06 AM in response to Topher Kessler
    Level 2 (306 points)
    Mac OS X
    May 10, 2015 9:06 AM in response to Topher Kessler

    This is impractical for me, unless there is a free app that will monitor such things (I'll look). I will say that I have lived in places where power outages were a constant problem, but In have never  noticed that here.

  • by benwiggy,

    benwiggy benwiggy May 10, 2015 9:08 AM in response to Niku
    Level 4 (1,430 points)
    Mac OS X
    May 10, 2015 9:08 AM in response to Niku

    Niku wrote:

     

    the job will have to be started again from the beginning.

    I started indexing my hard drive around 2:15 PM and I went to bed at 11:35 PM. At that time, 48,000 files had been scanned, and 46,692 files had been "handled," whatever that means.

    What job? What exactly have you set the computer to do overnight?

    Indexing? Spotlight indexing, or something else?

    Where are you reading this information about the file numbers?

    Are you running 10.10.3? What Mac model?

  • by Niku,

    Niku Niku May 10, 2015 9:13 AM in response to Allan Jones
    Level 2 (306 points)
    Mac OS X
    May 10, 2015 9:13 AM in response to Allan Jones

    This is not likely, but I'll check. It's just that only a few months ago, I took my computer to an Apple store because I couldn't get it started. They couldn't find the problem, but in the course of their examination they tested it and cleaned it. The end of that story is that I later had to pay $140 for a house call. The problem was just a loose connection. This is why problems are so often resolved with a kick or a thump.

  • by Niku,

    Niku Niku May 10, 2015 9:33 AM in response to benwiggy
    Level 2 (306 points)
    Mac OS X
    May 10, 2015 9:33 AM in response to benwiggy

    I was indexing my hard drive, but not for Spotlight. I just recently re-indexed Spotlight, but I now think the method I used didn't do the job properly. I say this because I remember another time I indexed Spotlight, and it took hours. Anyway, the solution may be easier than I had thought. I have now changed the setting of Energy Saver to NEVER. Hopefully, this will do the trick, if not, I'll be back. So, right now, I'm going to again try to install Email Archiver. I'm also going to re-index Spotlight using another method. This is the method I used: https://support.apple.com/en-us/HT201716

  • by benwiggy,

    benwiggy benwiggy May 10, 2015 9:44 AM in response to Niku
    Level 4 (1,430 points)
    Mac OS X
    May 10, 2015 9:44 AM in response to Niku

    1. Spotlight indexing may well take hours.

     

    2. "Indexing, but not for Spotlight." Eh?

     

    3. The "Never" bit in Energy Saver refers to SLEEP only. Sleep will not "power off" the computer, and won't stop an ongoing process. What you describe is not Sleep.

     

    4. The part of Energy Saver you were asked to check is in the "Schedule" button.

  • by Niku,

    Niku Niku May 10, 2015 12:20 PM in response to benwiggy
    Level 2 (306 points)
    Mac OS X
    May 10, 2015 12:20 PM in response to benwiggy

    2. No, I'm going to re-index Spotlight after I finish with Email Archiver.

    3.I knew that. I knew that it's probably clutching at straws, but what else can I do? Fortunately, my Email Archiving indexing is going much faster this time. It started out like a "house afire," but it has slowed down. Even so, I have now scanned 58,000 files after 49-minutes, while I only got to 48,000 after six hours yesterday. I now see that when 73,769 files have been scanned, the job will be done.

  • by Topher Kessler,

    Topher Kessler Topher Kessler May 10, 2015 5:43 PM in response to Niku
    Level 6 (9,866 points)
    May 10, 2015 5:43 PM in response to Niku

    I'm not saying its solely your wall power. Your Mac has a device in it called a Power Supply, which if failing may cut power to your system randomly (and eventually will). This may be spurred by poor wall circuits, so that's why I recommend trying another outlet or circuit, or even a UPS to even out any poor wall circuitry. It may also be spurred by high activity on your Mac that draws more power from the unit than usual. If the problem is from the power supply unit in your Mac, then it may continue to shut off randomly until you have it serviced.

     

    There are no apps that will properly monitor this, as it's a problem well beyond the system's ability to monitor. There may be some indication in console logs about an unexpected power event, but that will likely be all that indicates such problems.

     

    I'd say again keep it monitored, but if it continues despite settings changes, then you likely are experiencing a hardware fault.

  • by Niku,

    Niku Niku May 10, 2015 6:18 PM in response to Topher Kessler
    Level 2 (306 points)
    Mac OS X
    May 10, 2015 6:18 PM in response to Topher Kessler

    Well, the emergency is now over. Only a minute or two ago, I finally succeeded  in archiving all 73,780 files, so I won't have to worry about having to start all over again. I don't know what to do with them at the  moment, so I won't do anything until I get instructions from the distributor/maker of Email Archiver. I just can't risk doing anything wrong and regretting it. I'm still interested in  finding a way to avoid unwanted shutdowns, but I now have time to deal with that later. Thanks for your advice.

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