G.C.Thompson

Q: Mac Mini restarts: Previous Shutdown Cause: -2?

Hi folks,

 

I have a headless, second-hand Mac Mini (Late 2012) running Mavericks (10.9.2) which I've been trying to get stable for some time now. Two or three times a day it restarts for no (apparent) reason and until now I've not been able to spot any pattern. I've run full Apple Hardware Tests and no problems reported there.

 

Monitoring the logs, though, I've noticed that every unexpected restart is followed by a startup log that contains the text 'Previous Shutdown Cause: -2'. I've searched for this everywhere I can think of but haven't found anything.

 

Does anyone know what the mysterious '-2' is? Any pointers would help so I can try and troubleshoot the various elements of the system.

 

FYI the Mac is connected via Ethernet to the LAN, wireless is disabled. The Mac basically runs RealVNC (to get around Screen Sharing problems) and Air Video Server (to watch video on an iPad).

 

Any advice very much appreciated!

 

Message was edited by: G.C.Thompson

Mac mini, OS X Mavericks (10.9.2)

Posted on Mar 24, 2014 10:54 AM

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Q: Mac Mini restarts: Previous Shutdown Cause: -2?

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  • by G.C.Thompson,

    G.C.Thompson G.C.Thompson Mar 26, 2014 4:54 AM in response to G.C.Thompson
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    Mar 26, 2014 4:54 AM in response to G.C.Thompson

    I should add that I have iStat Menus running on the Mac and nothing apart from the CPU DIE is above 40 degrees, and the CPU DIE is idling at 41.

     

    I've left it running without using it for a couple of days now, and no restarts. I plan to put an HDMI/VGA headless dongle together by the end of the week and will see if that has any impact on the behaviour.

     

    I've since found a few posts indicating that -2 could indicate a problem with the logic board, but they were for different hardware (MBP classic, I think). With this Mini being out of warranty I'd hope that's not conclusive!

  • by G.C.Thompson,

    G.C.Thompson G.C.Thompson Apr 8, 2014 1:35 AM in response to G.C.Thompson
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    Apr 8, 2014 1:35 AM in response to G.C.Thompson

    Hi again; basically a post bump in the hope that someone can help me here?

     

    I've now connected the Mini to an HDMI display and removed RealVNC to take that out of the equation. So, I'm just using straight screen sharing.

     

    The Mini has restarted once every couple of days over the last couple of weeks, and every time I get 'Previous Shutdown Cause: -2' in the logs.

     

    To be this consistent there has to be some concrete problem - but I don't know where to start looking.

     

    Please, is there anyone who can help suggest what the '-2' is associated with?

  • by G.C.Thompson,Solvedanswer

    G.C.Thompson G.C.Thompson May 2, 2014 11:26 PM in response to G.C.Thompson
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    May 2, 2014 11:26 PM in response to G.C.Thompson

    Well, almost one month on but I've resolved the issue and wanted to leave a record in case this discussion turns up in someone's search for 'Previous Shutdown Cause: -2'.

     

    The problem was caused by some replacement RAM; I'd upgraded the 4GB that came with the Mac Mini to 8GB from Crucial. When I swapped the original RAM back in, the restarts stopped happening. (I repeated the tests with the original RAM and Crucial RAM a few times to make sure it wasn't just a seating problem.)

     

    Bear in mind that the RAM passed Apple's diagnostic tests and several runs of memtest. To be honest I didn't expect the Crucial modules to cause a problem as their products have always worked flawlessly in all the memory upgrades I've performed or helped with.

     

    Anyway, the evidence suggested otherwise, so I RMA'd the RAM with Crucial (great service as always), and the replacement DIMMs are now in the Mac, which hasn't restarted of its own accord for about a week

  • by mcfetty,

    mcfetty mcfetty Jul 24, 2016 6:47 PM in response to G.C.Thompson
    Level 1 (8 points)
    Notebooks
    Jul 24, 2016 6:47 PM in response to G.C.Thompson

    After about 3 years of use, my mid 2012 MacBook Air started randomly powering off. I am getting the Previous Shutdown Cause -2 error after every crash. It seems to be temperature related, so my question is: was your Mac running hot (or at least reasonably warm) at the time of your restarts? Mine seems to crash when cpu core temps push into the low 70s (celsius). Note: from what I gather they should be fine until 100 degrees.