27" i7 iMac random shutdown. Fun!

Discussion in 'iMac' started by robotkiller, Dec 31, 2009.

  1. robotkiller macrumors 6502

    robotkiller

    Joined:
    Oct 25, 2009
    #1
    So my iMac has developed this awesome new feature. Two or three times a day it will decide to restart itself. There is no interruption in power and the speakers attached to the same outlet do not turn off, so it appears the problem is isolated to the computer itself. I am typically surfing when this happens, luckily no mission critical stuff has been lost.

    Anyone else with this issue? I should be expecting iMac #4 in a couple of weeks, so I suppose I'll just have to deal with it in the meantime.
     
  2. JacaByte macrumors 6502

    Joined:
    Dec 26, 2009
    #2
    If this were any other computer (e.g. not a mac) I'd suspect either overheating issues (chipset bracketing automatically shutting down system before heat damage occurs) or a bad power supply. Since the bracket on PCs is usually 70ºC, and I know reports of Macs that have reached temperatures as great as 107ºC (suffice it to say: don't do that) without shutting themselves down, I think a power supply is more than likely the issue.

    If it's still covered under Applecare, send it in for the Apple lackeys to take a look at. They'll either find the defective part and replace it or send you an entirely new machine if it is covered.
     
  3. robotkiller thread starter macrumors 6502

    robotkiller

    Joined:
    Oct 25, 2009
    #3
    This was my immediate thought as well. I've been monitoring temperatures and they don't seem too far out of line. All temps less than 60 degree C.
     
  4. rigid macrumors regular

    Joined:
    Sep 28, 2008
    #4
    This was happening on my 24" imac for about a week. It was like there was a laser targeted emp effecting only my imac.
     
  5. Travisimo macrumors 6502a

    Joined:
    Dec 22, 2009
    #5
    This could be either a hardware or software issue, and may be hard to pinpoint. If you are not under heavy load when it happens, I wouldn't immediately suspect a power supply but it certainly could be. Do you have boot camp installed? You could always try booting into Windows (or another OS) or even from the OSX cd and see if it still does it.

    I would also try unplugging all unnecessary USB/Firewire devices to eliminate the possibility of a conflict there.

    You say it reboots, not shuts down, right?
     
  6. robotkiller thread starter macrumors 6502

    robotkiller

    Joined:
    Oct 25, 2009
    #6
    Yeah, it restarts - basically it clicks off to a black screen and a few seconds later you hear the boot gong. I've reset the PRAM (not that I think this will help) and we'll see what happens.

    One thing I've considered is the firmware update -- I never had this problem until I installed it. I recall it first happening shortly after first updating it.
     
  7. primehifi macrumors newbie

    Joined:
    Jan 10, 2010
    #7
    In the past three days my imac i7 has done the exact same thing twice.

    Coincidence only, but I'll put it out there, both times I was actively using firefox when it just died, reboot and everything was fine. Nothing else was active and the fans were not even on. Core temp I can confirm to you was 28 degrees Celsius, ambient 14, hdd 22.

    The only update I do not have installed is the Graphics firmware update.

    I'm confident it was not a power bump as the iMac is on a back-ups.

    :(

     
  8. Ecoh macrumors 6502a

    Ecoh

    Joined:
    Oct 30, 2009
    Location:
    USA
    #8
    My i7 restarted only once and it was about 5 minutes into I using Firefox. It has not done that any other time, since then I have installed the firmware update and installed the latest version of Firefox.
     
  9. primehifi macrumors newbie

    Joined:
    Jan 10, 2010
    #9
    hrm.

    maybe Firefox is the culprit ? If it happens a third time while using FF I'll begin using Safari and see if it happens then.
     
  10. senseless macrumors 68000

    senseless

    Joined:
    Apr 23, 2008
    Location:
    Pennsylvania, USA
    #10
    I posted this in another thread. In the last 3 days, I've had 2 resets, while clicking on the facebook newsfeed in Safari. I've done heavy load video encoding that bakes this machine, without any problems. Heat does not seem to be the issue for me.
     
  11. was2aks macrumors newbie

    Joined:
    Nov 29, 2009
    Location:
    USA St. Louis, MO
    #11
    RE: i7 iMac random shutdown...Me too

    My i7 has restarted about 3-4 times in the past 6 days. All while my wife was surfing, not pushing the machine. I have a week 50 machine with all software updates installed. I've pushed the machine doing batch processing and exports from Aperture without issue.

    One additional piece of data, my wife does use Safari on facebook. I need to gather some log info next time it happens, but I can confirm the printer and modem did not go out with the iMac, and they're all on the same power strip. Strange.
     
  12. iindigo macrumors 6502a

    iindigo

    Joined:
    Jul 22, 2002
    Location:
    San Francisco, CA
    #12
    I could be totally wrong, but it sounds like the issue may lie in Javascript (it's the only thing I can think of that makes Facebook stand out among other sites). Try disabling Javascript in your browsers and see if it makes a difference.
     
  13. iindigo macrumors 6502a

    iindigo

    Joined:
    Jul 22, 2002
    Location:
    San Francisco, CA
    #13
    I could be totally wrong, but it sounds like the issue may lie in Javascript (it's the only thing I can think of that makes Facebook stand out among other sites, as it uses Javascript extensively. Try disabling Javascript in your browsers and see if it makes a difference.

    Sorry for the double post, my computer was acting up.
     
  14. primehifi macrumors newbie

    Joined:
    Jan 10, 2010
    #14
    ugh.... woke up this morning not only to an imac that was turned off entirely but also to a 3GS iphone which was also stone dead.

    restoring iphone now (the dreaded "my iphone won't boot past apple logo" scenario).

    As I said, my imac was also off this morning. Hit the switch on the back and got it on, no issues there. Opened firefox and it restores the last open tabs, first one it shows me.

    Facebook.
     
  15. HLdan macrumors 603

    HLdan

    Joined:
    Aug 22, 2007
    #15
    It's a possibility you had a power outage over night.
     
  16. Btom macrumors 6502a

    Joined:
    Nov 19, 2009
    #16

    Sorry to mention this, but you guys sound like a typical PC crowd. Random crashes while WEB SURFING??
    Is Mac really that much different from a regular PC, Gold Leopard, or not?
    I am really having some serious second thoughts...

    Tom B.
     
  17. grooveattack macrumors 6502a

    Joined:
    Jan 9, 2008
    #17
    its your PSU losing it for just a second. in your system prefs switch off "auto restart after power cut" if your computer goes off but has no restart its a PSU fault.

    known 27" problem
     
  18. primehifi macrumors newbie

    Joined:
    Jan 10, 2010
    #18
    imac is on a ups. Unless the power went out for several hours (imac is the only thing on the ups, so it's got a lot of time), which it didn't because my old school digital clock without a battery, three nas's and other stuff did not lose power.
     
  19. robotkiller thread starter macrumors 6502

    robotkiller

    Joined:
    Oct 25, 2009
    #19
    My replacement iMac has been fine, but I isolated the old iMac's problem to Safari. When I used Chrome exclusively, there were no more restarts. I don't use Firefox, so I cannot say how it would act. I do not think this is a hardware issue that is necessarily specific to the 27". When I ran the thing in Safe Mode, I had no problems, so it appears to be software.

    So for those having this problem -- try using Google Chrome and see if it fixes the problem.
     
  20. archipellago macrumors 65816

    Joined:
    Aug 16, 2008
    #20

    What if you don't want to use Chrome..?
     
  21. archipellago macrumors 65816

    Joined:
    Aug 16, 2008
    #21

    Yes it is different.

    My home built Win 7 PC costs a tenth of an i7, it doesn't crash or freeze and the screen is uniform in colour... ;)

    btw. only 2nd thoughts...?
     
  22. robotkiller thread starter macrumors 6502

    robotkiller

    Joined:
    Oct 25, 2009
    #22
    why do you care
     
  23. archipellago macrumors 65816

    Joined:
    Aug 16, 2008
    #23
    does that mean you don't have an answer.. ? ;)
     
  24. robotkiller thread starter macrumors 6502

    robotkiller

    Joined:
    Oct 25, 2009
    #24
    [​IMG]

    archipellago, I've home built PCs since I was 12 years old, going back to DOS 4.0. If you think that PC users never troubleshoot and experiment in order to isolate a problem, then you are completely naive. The point of this thread is to isolate the problem and share experiences therein. All computers (even Windows!) have problems and we are trying to figure out the problem and, hopefully, a real solution. Using Chrome instead of Safari is an experiment. Surely you can fathom this. If you have nothing constructive to contribute, then may I respectfully suggest that you get lost?
     
  25. archipellago macrumors 65816

    Joined:
    Aug 16, 2008
    #25

    I fully understand what you are trying to do but it makes no sense nor gives a solution.

    outcome from your experiments will be either a/ or b/

    a/ Chrome solves the problem, machine doesn't crash. User doesn't like Chrome so machine has to be returned.
    b/ Chrome doesn't solve problem, machine has to be returned.

    anyway I thought Macs just worked?

    without need for much troubleshooting (if any) or the need to use (or not use) specific programs?

    the real solution is to return for refund and if OSX is needed then wait for rev B, build a Hack or a different machine...... but seeing as Apples' desktop range is somewhat anaemic the choice is limited.
     

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