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Berry with an "A" Level 1 Level 1
• 27" 2.8 GHz Intel Core i7 / 8gig / 1TB
• OS 10.6.3 (about to update to 10.6.4)
• All firmware updates have been applied according to software update
• 3 external drives: 1-320 gig 800fw / 1-TB USB 2.0 / 1-500gig USB 2.0


I've been running with this configuration ( 3 extra drives) since approximately December with no issues. Out of the blue... only running Aperture and Safari - my iMac JUST SHUTS off- WITHOUTwarning. It acted as though I was running a MacBook and the battery going dead/asleep. That's how random and sudden it shut down - NO WARNING. I did have the iMac asleep for about three hours before coming back to it to start working again when it shut down, but it should have even been cool.

I only started reading around on the web to see of other incidents after this random shut down this evening, but I can't find anything specific. I've found A LOT of similar things - all seemingly related to "HEAT."

And heat seems to be a certain issue recently - in the last day or two. Today I noticed my top back side to be hot, which isn't uncommon, however, it became so hot I really wasn't able to keep my hand on the top back. I've also noticed A LOT of spinning beach balls, and lots of processor delay! Heat??

There are NO energy saver pref's set to automatically shut it down. The power was and is firmly set. There are no network settings, nor access to the iMac to have it shut down. It is not shared with anyone on the network.


• Today, I grabbed a couple temp / monitor widgets and am trying to watch the data. All components seem to be at/around/below 140 degrees F with ambient air at 77 degrees. I don't know numbers, but that all seems reasonable.
• Going to update to OS 10.6.4 (doubt that's it!!)
• I'm going to run the hardware test from my disc to see if ANYTHING. 8-p
• AND... I'm going to call Apple to set up a case. It's still full under warranty, and I have 2 more years of AppleCare on it. But there's been too many things pointing to hardware to call this a software issue.

I've dodged all the display issues with my iMac, but now.. I'm a bit hacked knowing how much I spent on this thing, with the initial DELAYS I went through, ordering it before it had even been released!

?? QUESTION ??_____________________________________________________________________

So, has anyone else been having this issue, heard of a solution, seen anything on Apple's website of known issues ??

( Grumbling bout my Mac)

Which one of twelve??, Mac OS X (10.5.6), ever hear Newton?!! ;-) One of those, too!
  • Barry Hemphill Level 8 Level 8
    Hi Berry with an "A" (that is a riot, I have the same problem):

    You have been most thorough in your post and have documented the problem well.

    AND... I'm going to call Apple to set up a case. It's still full under warranty, and I have 2 more years of AppleCare on it. But there's been too many things pointing to hardware to call this a software issue.

    I completely agree with your assessment and course of action. Even if others have experienced similar problems, my reaction would be to suspect hardware as a cause. Be sure to have your complete documentation at hand when you contact Applecare.


    (with an "A")
  • Berry with an "A" Level 1 Level 1
    *> Barry Hemphill wrote:*
    I completely agree with your assessment and course of action. Even if others have experienced similar problems, my reaction would be to suspect hardware as a cause. Be sure to have your complete documentation at hand when you contact Applecare.

    My thoroughness and layout of information derives from being a former Apple Customer Relations Representative. I will be sure to have everything laid out and tested before contacting Apple

    +*ISSUE: ________________________________________________*+
    iMac shuts down WITHOUT warning as if it were a MacBook with the battery going dead/asleep.

    +*INFORMATION: _______________________________________*+
    • 27" 2.8 GHz/ Intel Quad Core i7 / 8gig / 1TB / OS 10.6.4
    • All firmware updates have been applied according to software update
    • 3 external drives: 1-320 gig 800fw / 1-TB USB 2.0 / 1-500gig USB 2.0

    *+UPDATE: _____________________________________________+*
    • Monitoring temps, current after waking 64 ambient/105 overall avg.
    • Updated to OS 10.6.4
    • Hardware test ran from disc. Nothing showed failure.

    • I will try to find time to call Apple today to set up a case regarding this issue.

    +*RESOLUTION: _______________________________________*+
    I would still like to know if anyone else has had this issue, or similar, and if they've talked with Apple tech support or otherwise to know if there is some kind of known issue.
  • Francisco Pereira Level 1 Level 1
    Today the same happened to me.
  • ZigZagLens Level 1 Level 1
    I had this happen with mine, just a couple weeks after I bought it. Same config - 2.8GHz, i7, 8GB RAM, 1TB.

    There are several threads about it, suspiciously dating back to the SMC firmware update issued in April. You might want to see this one: and the threads referred to therein.

    You'll also notice in those threads that users with the complaint also have 27" i7s with 8GB RAM.

    Anyway, finally one morning it wouldn't wake from sleep - nor start up (except occasionally showing the gray screen then shutting off again) and I brought it back to Apple.

    They had it for several days. Initially when I called to check on it, they said they couldn't replicate the issue and it was working fine (even though the Genius taking it in personally witnessed it), and said I should come pick it up.

    I refused, and asked to speak with the guy who took it in. He said they "reseated the RAM" so it was probably the RAM. I wasn't buying that, so I pushed him to dig deeper. Eventually they replaced the power supply and the optical cable (at my insistence/urging - I don't think this was done for any particular reason other than to take a blind swing at possible causes.)

    Anyway, I've had it back probably six or eight weeks, and it hasn't happened since - BUT - I also haven't applied the SMC firmware update since getting it back - despite Software Update urging me to at least daily.

    If I had the courage, I'd apply the SMC firmware update again and see if the problem returns. But I don't want to be without the iMac for another week or longer - this is my primary machine I use at work.
  • elmac Level 5 Level 5
    Hi, it will be interesting to see what results you get - Knowing the System!
    In my experience Apple never acknowledge an Issue (unless it is real serious)
    I used to work with an Apple Service Rep -> 3 Macs on his w/bench -> ALL with the same issue"'
    he told a Mac user @ the Service desk with the """Same Issue"" ""I have NEVER encountered That Issue...
    He was straight faced..Me I walked away.. In all honesty I have never in 10years known Apple to walk away from an Issue when Corp/Customer service became involved...My experience with my Laptops
    was gratifying (Two 1yr olds replaced with latest 2010 models)
    I feel your issue is down to a Power/Ballast unit within the PowerPack...L
  • tjtrapp Level 1 Level 1

    I'm having a similar random shut down problem. If I power on the computer, it just turns off. It's currently powering off before I can login but earlier today it was powering off well after I had logged in and began to work.

    After it shuts down, the only way I can power it back on is to unplug it for a few minutes... but the cycle continues. It powers on and before the login screen appears it powers off.

    At first I thought it may be due to the temp, so I let it warm up for a bit but that didn't seem to help b/c the problem continues.

    I tried plugging it into different power sources: a surge protector, a wall outlet, a different wall outlet. None of the changes allowed the computer to work normally.

    I would like to try a different power cord, but need to go get one from the store so I might as well just bring the box w me :/

    Any idea to prevent a trip to the store would be super.

    Thanks in advance.
  • Berry with an "A" Level 1 Level 1
    As I type this message I'm setting up a call back from Apple since I still have phone support through my extended Apple Care coverage.

    In starting the process, you have to select a series of possible issues that you're experiencing. I found it interesting that one of the auto-topics to pick from is titled for one of the possible issues I found this morning: "Intel-based Macs: Resetting the System Management Controller (SMC)" seen at:

    This "might" be the answer to correct this issue. In my searching online with Apple this issue was showing to effect iMacs previously to late 2009 (not mine) however, I did apply all the firmware updates, including the latest SMC update, so it might make sense.

    I'm completing the tech support call back process and see what they say, and will report back here my results. I do NOT want my iMac just simply powering down out of the blue, NOR do I want to have to send it to Apple to have some tech's careless hands all over my baby.
  • Berry with an "A" Level 1 Level 1
    I feel this is going to require more than one update, so I'll start numbering my updates:

    UPDATE #1:

    I provided Apple with info and the issue, and set up a call back online. I usually have a good experience. I spoke with an Apple rep, with whom will be named "Jordon the Jerk." He read my notes, and without ANY trouble shooting, or further information said, "You have a heat issue, take it into an Apple store." That's it?!?

    Not satisfied I initiated a second call back with very few details provided, and spoke with "Kevin." He wanted to begin trouble shooting, so I quickly provided all the trouble shooting info I had already performed. He basically concluded, and said, it sounded more like a software issue.

    He concluded I try either (a) Safeboot, which would supposedly clear out some of the cache in the system; whatever that meant, and/or (b) Reset the (SMC) System Management Controller, and/or (c) reinstall the operating system, which is nothing but a crock. That sounds more like a solution a PC geek would suggest.

    During my talk with Kevin said he was aware of this rare issue and on applying the Safeboot method to correct the issue - he had only rare success. The final step, I was told, should be to take is to check it out for a hardware issue.

    It sounds as though Apple is aware of some type of issue, and they're just not saying anything about it yet.

    I'm going to call Apple Customer Relations to see if I can get this escalated to a higher Tier of Apple tech support to see if I can get some real direction before I start lugging my 27" all over the place.

    Message was edited by: Berry with an "A"
  • Berry with an "A" Level 1 Level 1
    First, a precautionary Note:
    Apple "Call Directors" are outsourced, and from what I experienced today are idiots and liars. When asking for Customer Relations the first guy represented himself as Customer Relations. I knew he wasn't. I said he was a liar and hung up on him. The next gal transferred me to CPU tech support, even though I specifically stated "Customer Relations." So just keep your guard, know you're calling and who you're speaking with.

    UPDATE #2:
    I still don't think Apple knows about this issue enough, or they're just not saying that they're seeing it more.

    I spoke with a senior tech support advisor who said he believed it was a heat issue. It could be because the number of periph's I have attached, and that I might try unplugging those one at at time. I personally don't think that's it since I've been running the same configuration for over six months.

    To his credit, the Sr. tech said he wasn't convince of that, nor did he think it was a software issue, although he also suggested as a trouble shooting step - was to do partition my drive and try running an OS from there. Both suggestions kind of defeats the purpose of being able use my Mac and applications. Since this issue has only happened twice, he said he would rather have me trouble shoot on my own some more, rather take in for service and then have repairs not be able to duplicate the issue.

    The last thing I did before contacting Apple today was to do a SMC update, and the Sr tech I spoke with said that that step very well could resolve the issue. I also think the same since I just did the SMC firmware update a little over a month ago, and this issue just started a week ago.

    Sorry... that's all I got so far. I'm just hoping I don't have any more random shut downs, and hope the SMC reset does the trick. I am very interested if anyone else has any better, any more info, any better solutions they've heard or come accross?
  • Berry with an "A" Level 1 Level 1
    UPDATE 3:

    I know others have cross referenced other posts, so I'm doing it as well here with the one I started. I suggest everyone start and keep this cross reference list and maybe paste it at the end of every one of your own posts regarding these similar issues. Maybe Apple will have to pay attention!

    27-inch / 27" iMac Random Shut down:

    Random Restarts on Intel based iMac

    Sudden restarts and shutdowns on iMac

    27" Core i7 iMac blacks out then restarts itself for no reason:
  • Berry with an "A" Level 1 Level 1
    UPDATE #4:

    I neglected to mention what I think is an important aspect to this issue of random or "spontaneous" shut downs and restarts.

    When I was setting up my call back from tech support... when you're selecting the issue you're having.... Apple, now does in fact have a roll down on this EXACT issue. So I don't know how Apple could be denying this issue, nor aggressively addressing it?! ( SEE BELOW )

    I've never had this issue up until a month ago... AFTER I applied the SMC firmware update. Most posts I've read are from people who were experiencing this issue before the update even came out.

    My guess is - that Apple was trying to address this random, or "spontaneous" shut down and restart issue, so they created the SMC firmware update. When they did, and everyone applied it, they created MORE problems for people like me. NOW... my iMac randomly shuts down.

  • Berry with an "A" Level 1 Level 1
    I was told this was more likely a heat issue, so why then is Apple replacing optical cables, logic boards, and other random parts? What is REALLY being done to address this issue? I'm still looking for anyone who has any more specific info on this issue, and if Apple has corrected it for them.
  • Berry with an "A" Level 1 Level 1
    Adding another, seemingly related link (far below) regarding high fan speed. It all seems related to the SMC:

    *27-inch / 27" iMac Random Shut down:*

    *Random Restarts on Intel based iMac*

    *Sudden restarts and shutdowns on iMac*

    *27" Core i7 iMac blacks out then restarts itself for no reason:*

    *21.5' iMac fan speed is to fast*
  • Chris Beall Level 1 Level 1

    Based on your previous posts, I'm going to try to summarize your problem to make sure my understanding of it is correct. Please correct any errors.

    27" 2.8 GHz Intel Core i7 / 8gig / 1TB
    All software and firmware up to date.
    3 external drives: 1-320 gig 800fw / 1-TB USB 2.0 / 1-500gig USB 2.0

    Primary symptom:
    System shuts down without warning. Frequency: twice, in one week.

    Secondary symptoms:
    Fans "kick WAY too much sometimes". (from a post in another thread).
    Processing slowdown (slowed response, beach balls).
    System very hot to touch at top of enclosure.

    Problem did not appear until after recent SMC firmware update.
    Ambient temp 64-77 F.
    "All components" temp ~105-140 F.
    Hardware tests pass without error.

    Corrective actions tried and results:
    28 Jun 2010 - SMC reset (no failures since)

    What is your current SMC Version?
    Have you noticed high fan speeds (noise) since applying the most recent SMC firmware update?
    What, if any, software do you have installed that displays system temperatures and fan speeds?
    What, if any, software do you have installed that controls fan speeds?

    Chris Beall
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