Apple Shutdown Suddenly :(

Discussion in 'iMac' started by hack3rcon, May 20, 2015.

  1. hack3rcon macrumors regular

    Nov 26, 2014
    Hello Expert.
    When I worked with iMac for Some hours it shutdown suddenly, How can I find the root of problem?

    Thank you.
  2. keysofanxiety macrumors G3


    Nov 23, 2011
    1) Check HDD SMART Data. This will check for corruptions on the HDD. You can download and run SMART Utility here: If there's anything other than 'Passed' is displayed, the HDD is corrupted, and there's the root of your problem.

    2) Verify your volume. To do this, open Disk Utility (search for it in Spotlight, or go to Applications>Utilities>Disk Utility). Then single-click your volume (typically called Macintosh HD) to highlight it, and then click the 'Verify Disk' option along the right-hand side. If it comes up with red writing, we'll need to repair the disk. Quote this if that's the case and we'll take you through how to do that.

    3) Restart your iMac, with the option 'Reopen windows when logging back in' disabled. This means that if there's a background software conflict or memory leak causing the problem, it won't come back up. Highly unlikely to be causing the issue, but worth getting into the habit of doing it.

    4) Check for software updates for your OS (Apple menu>Software Update on Mavericks or earlier, or Apple menu>App Store on Yosemite). There may be an update for the OS. Again highly unlikely to be causing the issue, but it's worth checking.

    Other issues causing it could be:

    - RAM
    - Faulty logic board
    - Overheating

    So once you've had an opportunity to try the above, please quote this as we can do a number of additional troubleshooting steps on the RAM/MLB/temps if no problems are found.
  3. hack3rcon thread starter macrumors regular

    Nov 26, 2014
    When it want shutdown, I heard Fan noise and I sense Fan worked with High Speed.
  4. keysofanxiety macrumors G3


    Nov 23, 2011
    Okay. Please could you try the requested diagnostics and advise if there is a problem identified in any of the steps?

    Also how old is your iMac? You can verify the exact model by typing your serial number into this website:
  5. hack3rcon thread starter macrumors regular

    Nov 26, 2014
    I Paste my serial number in above link and show me :

    "iMac (21.5-inch, Late 2009)"
  6. keysofanxiety macrumors G3


    Nov 23, 2011
    Okay. Did you manage to run the diagnostics as outlined in my original post? Any errors detected? If you're having any problems just let me know.
  7. MartinAppleGuy macrumors 68020


    Sep 27, 2013
    Wouldn't have console listed the problem at the time it switched off?
  8. hack3rcon thread starter macrumors regular

    Nov 26, 2014
    I run this application and it show me a green message "PASSED". I executed test and show me "completed without error".

    What is your idea?
  9. macthefork macrumors 6502

    Feb 2, 2013
    If your fans started running at high speed, you could have an overheat issue, which can also cause unexpected shutdowns.

    Dust can accumulate within an iMac over time causing the overheat issue. The first place to check is the bottom of the iMac where the vents are. Look to see if they are clogged with dust. If they are you can gently try to vacuum the dust out. If there is excessive dust, the iMac may need to be opened and cleaned.

    You can also try a can of compressed air to blow dust out. But... do this from the top vents, not the bottom vents. If you try and blow dust out from the bottom vents, you'll just blow it further into the computer.

    Is this computer operated in a room where there is a smoker? How about pets. I've seen a Mac Pro absolutely covered internally with fine dander-like material and hair when the computer failed and was brought to me for repair. That one was in a home with numerous pets, including birds.
  10. keysofanxiety macrumors G3


    Nov 23, 2011
    Good morning Hack3rcon,

    Apologies for my belated reply. The purpose of running a Disk Verification & checking the SMART Data on the HDD is to identify whether anything is, or is not, faulty. As the hard-drive passed without problems and the disk verification passed, this means that neither the hard-drive nor the OS volume are corrupted, and we know that the problem is elsewhere.

    As the Macthefork above me has stated, due to the age of your machine and the symptoms it exhibited, the issue is likely to be related to overheating.

    Can we confirm how often this problem happens, or if it was just a one-off?
  11. Fishrrman macrumors P6


    Feb 20, 2009

    From what you have described above -- after checking hardware and finding it OK -- it sounds like something you were doing (could have been an app you were running, or might have been some kind of "behind the scenes" process) put your CPU into full power, it overheated (hence the fans running just before shutdown), and finally the computer shut down -because- of the overheating.

    How has it run since?

    It's possible it could have been a one-time occurrence due to the things you had running at that particular moment.

    What you might try:
    Download something called "Macs Fan Control":

    It will put into your right menu bar both the temp of the CPU and the speed of the fan(s).

    You can then keep an eye on both these parameters for a while, and compare temp/fan changes to what you are doing with the iMac....

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10 May 20, 2015