Lagoiski

Q: 27 iMac (2012) crashes and requires smc reset to turn on

My late 2012 iMac, i7 16gig RAM 27 inches keeps shutting down. It looks like as if it was unplugged. Happens randomly. Sometimes while playing Diablo 3, surfing facebook or using iphotos or other apps. Seems to not crash if just left on overnight and not been used.

 

In order to turn it on again I have to unplug it from the power line for like 30 seconds, only then it starts.

 

I have the settings set to restart on power failure, but it does not.

 

Happened a few times a few months back. I have installed a surge protector and it worked fine for like a month or two. However last 2 days it has shut down like 10 times...

 

Help would be greatly appreciated. I suspect hardware failure.

iMac (27-inch, Late 2012), iOS 7.1.1

Posted on May 5, 2014 9:44 PM

Close

Q: 27 iMac (2012) crashes and requires smc reset to turn on

  • All replies
  • Helpful answers

first Previous Page 24 of 28 last Next
  • by inge.a_son,

    inge.a_son inge.a_son Aug 5, 2016 4:25 AM in response to Lagoiski
    Level 1 (4 points)
    Desktops
    Aug 5, 2016 4:25 AM in response to Lagoiski

    One more client in the list:

    iMac (27', late 2012) OSX Yosemite 10.10.5

    1 To fusion drive

    3,4 GHz Intel Core i7

    8 Go 1600 MHz DDR3

    NVIDIA GeForce GTX 680MX 2048 Mo8 Go 1600 MHz DDR

     

    - the original Hard Disc has been changed after a total crash (apple-care 1st year)

    - the screen has also been changed (de-coloration in the lower corners and 20 insects, or black spots here and there, apple-care 3rd year)

     

    Right after the screen has been changed the problem of sudden shut downs started to appear... at first I didn't realise what was happening. I rarely turn off the computer, I rather put it to sleep or put the screen to sleep, so the computer can keep on working while I do the sleeping, but I remember sometimes finding the computer turned off in the morning. I was thinking maybe the electricity being cut off (happens often here in the countryside when there is a lot of windstorms) or that somebody else in the family turned off the computer...

     

    It took some while to identify this problem, but one day it happened when I was in front of the screen... and then it started to happen more often... two or three times a day.... by this time, unfortunately my Apple-Care has run out.

    I called them anyway, and they tried to do some things but nothing worked out (cleaning out all the preference files, starting in safe mode etc.)

     

    One strange thing I have noticed is: when trying to reset the P-Ram the computer shuts down "black out" after the first "gong" without finishing the procedure and then  the only solution to restart the computer is to unplug the electrical cord for 5 minutes... "SMC reset"

     

    Console : kernel[0]: Previous shutdown cause: 0

     

    Unplugging the computer over night is really helping to keep the computer working the rest of the day, but this is not a solution in the long run.

     

    I have to bring in the iMac to a service-center for observation and report. (at my charge)

    I will report here the solution they hopefully find.

  • by Sahastro,

    Sahastro Sahastro Aug 7, 2016 6:31 AM in response to Lagoiski
    Level 1 (4 points)
    Aug 7, 2016 6:31 AM in response to Lagoiski

    OK I am another one to the list with one of those shutdowns

     

    iMac (27', late 2012) OSX El Capitan 10.11.6

    3 TB fusion drive

    3,4 GHz Intel Core i7

    32 GB 1600 MHz DDR3

    NVIDIA GeForce GTX 680MX 2GB

     

    What I tried so far is to install the original RAM the iMac came with (8 GB), but with no change regarding the shutdowns. Next stept would be to change the power supply but what I read here so far I have only little hope that will change anything...

    Has anybody tried to change the SSD card on the motherboard that is part of the fusion drive yet ? I have read some have changed the HDD already what does not seem to help but I haven't read that anybody has changed the SSD card yet.

  • by Glasguy,

    Glasguy Glasguy Aug 7, 2016 6:44 AM in response to Sahastro
    Level 1 (12 points)
    Desktops
    Aug 7, 2016 6:44 AM in response to Sahastro

    I replaced my power supply and have not had any problems after running  a 24 hour Apple Service Diagnostics test. Highly unlikely that your fusion drive SSD & HDD are causing problem. Try connecting an external hard drive to your iMac and install OSX El Capitan on that external drive. Then boot OS X from the external HDD and confirm if you have intermittent shutdown when using OS X from external drive. 

  • by Sahastro,

    Sahastro Sahastro Aug 7, 2016 6:54 AM in response to Glasguy
    Level 1 (4 points)
    Aug 7, 2016 6:54 AM in response to Glasguy

    Ah OK good to know. I will try changing the power supply then...

  • by NickFromLE,

    NickFromLE NickFromLE Aug 7, 2016 7:03 AM in response to Sahastro
    Level 1 (22 points)
    Desktops
    Aug 7, 2016 7:03 AM in response to Sahastro

    It started with Safari Problems. Whenever I surfed the web with Safari, I got these shutdowns.

    Then I switched to firefox which solved it for some weeks but now its coming back.

     

    I got this solved again (don't now for how long) witch setting the fan to max rpm. Its louder, of course but since then not a single shutdown anymore. That brings me back to temp. problems which are maybe the cause. I will let you know when the shutdowns return. So far so good.

  • by Glasguy,

    Glasguy Glasguy Aug 7, 2016 7:36 AM in response to NickFromLE
    Level 1 (12 points)
    Desktops
    Aug 7, 2016 7:36 AM in response to NickFromLE

    Nick,

     

    Don't think temp is the cause, most likely your power supply unit is not powering yourAirport ( WIFI ) Card properly. I also  noticed during my diagnostic testing that my Airport Card failed wake and sleep tests, those wake and sleep tests are a good indication something is wrong with power. 

     

    When I replaced my power supply unit my iMac passed tests on the Airport Card.

     

    If temp was the main cause, then the shutdowns would be predictable. These iMacs have plent  of sensors, on reaching a specific  temp then your iMac would always shutdown, that's not the case here.  The shutdown cause error 0 ( sudden loss of power ) logged also points to the PSU.

  • by NickFromLE,

    NickFromLE NickFromLE Aug 7, 2016 7:49 AM in response to Glasguy
    Level 1 (22 points)
    Desktops
    Aug 7, 2016 7:49 AM in response to Glasguy

    Glasguy,

     

    understood.

    But as I read so far in this thread there are some people who changed their PSU and after some time the shutdowns happened again. You mean this problem comes back from time to time or is there a bad amount of iMac models with the "wrong" or not working PSU? As I read, this also affects 5k iMacs, so this is a problem of more then one model?

    I agree with you, if temp would be the main cause you could force shutdowns only by high temp. Thats def. not the cause. But it may affect the problem here - lower temp may let the PSU work in more stable parameters.

    I just down know honestly what to do, I just can try things out and when it works, we all can be happy. Its so nerve wracking with that shutdowns...

  • by Glasguy,

    Glasguy Glasguy Aug 7, 2016 8:05 AM in response to NickFromLE
    Level 1 (12 points)
    Desktops
    Aug 7, 2016 8:05 AM in response to NickFromLE

    Nick,

     

    I seems that 27" iMac 2012 up to Retina have reported problems with intermittent shutdown. The 27" iMac service manual is the same for 2012 /2013/ late retina 2014. I'm wondering if Apple use's more than one manufacturer to supply PSU's for these iMacs, also wondering if they use refurbished PSU's for replacements.  My faulty  PSU is made by delta Electronics, my replacement is made by LiteOn.  That makes sense what you mention that low temps may let the PSU work in more stable parameter. It a spoiler having uncertainty and no confidence when using the machine.

  • by NickFromLE,

    NickFromLE NickFromLE Aug 7, 2016 8:46 AM in response to Glasguy
    Level 1 (22 points)
    Desktops
    Aug 7, 2016 8:46 AM in response to Glasguy

    Thanks for that info - then it makes sense that all iMacs beginning from 2012 having these problems.

    Just 10mins ago I exchanged my 1TB Harddrive with a 1TB SSD. With this I saw A LOT of dust in the iMac as it was mentioned above by other users. I tried to clean it up as good as I can. It really were flakes of dust and compressed dust. The fan was free, not jammed or something but of course also full of dust. Hopefully its now getting better. I also set fan speed back to default. The OS is controlling it now, we will see if strange behavior will occur. I'll drop a line if so.

  • by Glasguy,

    Glasguy Glasguy Aug 7, 2016 9:25 AM in response to NickFromLE
    Level 1 (12 points)
    Desktops
    Aug 7, 2016 9:25 AM in response to NickFromLE

    Nick,

     

    Can you confirm what brand your power supply is, does it look healthy when the dust is removed. Do you have white ingress marks on the PSU.

  • by NickFromLE,

    NickFromLE NickFromLE Aug 7, 2016 12:13 PM in response to Glasguy
    Level 1 (22 points)
    Desktops
    Aug 7, 2016 12:13 PM in response to Glasguy

    Glasguy,

     

    sorry but I just put in a new hard dive, I did not dismount the logic board the install it. Therefore I did not see any labeling of the PSU.

  • by ElBartolomeo,

    ElBartolomeo ElBartolomeo Aug 7, 2016 12:41 PM in response to Glasguy
    Level 1 (4 points)
    Aug 7, 2016 12:41 PM in response to Glasguy

    I did it.

    But shutdowns persists

  • by Beolion73,

    Beolion73 Beolion73 Aug 12, 2016 2:52 AM in response to ElBartolomeo
    Level 1 (4 points)
    Aug 12, 2016 2:52 AM in response to ElBartolomeo

    I simply cannot imagine that Apple does not know what the core of the problems is. They are so much in control of their products and the assembly of them, our problems must be known.

    I would not mind spending money on fixing my Mac, but I don't want to end up replacing part after part - and wasting lots of money - until the Mac is fixed.

    Apply should be able to point out that if you have PSU model xxx or CPU model yyy etc, then you should do zzz.

    Please, our son was just doing his homework on the Mac today and suddenly the Mac turned off. And since he did not know that he had to unplug the power for 1 Minute, he never got the computer turned on again.

    And he was furious that some parts of his assignment was lost, which I understand.

  • by partidacascalls,

    partidacascalls partidacascalls Aug 12, 2016 7:06 AM in response to Beolion73
    Level 1 (4 points)
    Aug 12, 2016 7:06 AM in response to Beolion73

    Well, I presume everybody has seen this notice. iMac (27-inch): AMD Radeon 6970M Video Card Replacement Program - Apple Support. Clearly Apple recognize the problem with our build, models but only those fitted with the AMD Radeon HD 6970M video cards . All of our models are based on the NVidia Card. When will Apple address this ?.

     

  • by Solidairs,

    Solidairs Solidairs Aug 12, 2016 7:23 AM in response to partidacascalls
    Level 1 (14 points)
    Aug 12, 2016 7:23 AM in response to partidacascalls

    Sadly does not apply. Suffering with a NVIDIA GeForce GTX 660M.

first Previous Page 24 of 28 last Next