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27-inch / 27" iMac Random Shut down

SPECS:____________________________________________________________________________
• 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

INFORMATION:____________________________________________________________________

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.

SUMMARY:___________________________________________________________________________

• 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 ??

Barry
( Grumbling bout my Mac)

Which one of twelve??, Mac OS X (10.5.6), ever hear Newton?!! ;-) One of those, too!

Posted on Jun 22, 2010 8:59 PM

534 replies

Jun 30, 2010 10:51 AM in response to Berry with an A

Barry,

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.

Environment:
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.

Observations:
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)

Questions:
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

Jul 13, 2010 2:23 PM in response to Berry with an A

If anyone's interested...

Since doing a SMC reset (shortly after my last BLACK OUT on 6/27/2010) I've not had my i7 27" go down on me. I've not worked it very hard, but the last time it blacked out - I wasn't working it hard then.

I've spoken with two upper tier tech support, the second was after Apple called me back today to follow up with the issue. So I don't know if that kind of call back is normal, or if Apple is checking up because they know there is some kind of issue of i7's just shutting down.

I was told from the upper tech support rep that: the report I was able to save after it restarted indicated the processor was trying to read a (generic) cache file and caused such a massive kernel attack, that to protect itself, the iMac shut itself down.

So, in short, I don't think Apple still knows what issue there is, what's causing it, nor how to resolve it. Hopefully though the SMC reset fixed my issue. Only time will tell, and thank goodness I have extended AppleCare!

Happy Mac'n

Jul 28, 2010 9:21 AM in response to Berry with an A

I received a similar call a couple weeks ago. Also, after holding out for a couple months since my "repair" - resisting the SMC firmware update - I applied it today. We'll see how things go.

burkanov

Level 1

10 points

Aug 20, 2010 12:34 AM in response to Berry with an A

I have the same problems: my brand new 27" iMac just shuts down 2-3 times in an hour. It has 16GB RAM and both 256GB SSD & 1TB HDD. Must bring it back to Apple and wait another 3 weeks until they fix it...

Paradoxx

Level 1

20 points

Aug 20, 2010 6:25 AM in response to burkanov

Hi Burkanov,

Are you using 3rd party RAM? It sounds like it could be a problem with 'bad' memory.

Aug 22, 2010 11:07 PM in response to Berry with an A

I am having the same problem. And so are one of my friends. I have tried resetting my SMC now, and I'll see if it gets better. My machine has turned its self off 9 times since i bought it. (4 months ago)

Aug 23, 2010 6:48 AM in response to Berry with an A

Hi everyone. I'm the one who started this thread. There had been a SMC firmware update few months back with Apple's software update. I personally believe, although Apple won't say, that firmware update caused my random shut downs. However, when I reset the SMC - that seemingly simple act - so far, has solved the problem.

Rarely do you see anyone from Apple officially comment within the forums, but I have had the top tier tech support actually talk with me on the phone. They actually called me back on it once, and after I told them what I had done, with the results I had, they seemed the issue was probably resolved.

The short of it is, a few weeks after I updated the firmware, my iMac just randomly shut down out of the blue - twice within a week. I thought it might be heat related because like others, my top left corner gets extremely hot.

After I reset the SMC my iMac doesn't seem to run as hot as it did, or at least to the point where I could actually hear the fans. But more importantly - my iMac has not shut down once on me since I reset the SMC. Because of this, and not having any further issues since, I'm going to mark this issue/question as answered.

Aug 23, 2010 6:50 AM in response to Berry with an A

As I mentioned in my very last post. I've not had any issues with my configured iMac since simply resetting the SMC. Not one random shut down since then.

Aug 23, 2010 4:41 PM in response to Berry with an A

Thanks so much for this detailed thread, Berry with an "A"!!! My work computer, exactly the same model as yours, had the same random shutdown problem for a couple of weeks. I went through the thread, and reset my SMC. It's been 2 days since, and I have NOT encountered the problem again. Hope this will solve others' shut-down as well.

Aug 25, 2010 5:06 PM in response to Loudwater

OK. It just happened to me a couple of times today again (twice restart, once shutdown, all random and the machine was pretty hot). I installed the security update that was released last Friday. Not sure if that was the problem. I reset the SMC and PRAM and NVRAM again, let's see if this helps. Maybe it's time for Apple to give us a new computer!

Aug 25, 2010 7:28 PM in response to Loudwater

Loudwater -

I don't know if last week's update is an issue with your restart and shutdowns... but two things:

(1) My iMac never did any random restarts... it only did shut downs. It acted like my MacBook Pro when I let the batter die... it acted as if it had a battery and just shut down.

(2) Although I'm not sure if last week's update did anything regarding the issue you're having, but I know one thing... shortly after I did the update... I think the same day... my iMac had the weirdest freeze up... basically a kernal attack.... dark gray screen washed down from the top to the bottom with all the different languages, and said I had to hold down my power key to force restart it.

I think that's happened to me... maybe once since getting this new processor i7. Too much of a coincidence thought ... right after the update last week!

Aug 26, 2010 3:58 PM in response to Berry with an A

Berry with an "A":

I believe the random restart thing was new. Before, it was only plain black screen shutdown - I understood what you were describing, and I'm 100% sure it was the same symptom. I reset SMC, and it just happened again to me today. The machine was scorchingly hot when it happened.

We are going to bring it in to an Apple Store tomorrow to have it checked. (The customer service, especially senior people, were being ******** and not telling us any useful information.) I'll post back if anything changes on my end.

burkanov

Level 1

10 points

Aug 27, 2010 7:26 AM in response to Paradoxx

Paradoxx wrote:
Hi Burkanov,

Are you using 3rd party RAM? It sounds like it could be a problem with 'bad' memory.

No, everything is original.

Message was edited by: burkanov

Aug 28, 2010 4:15 PM in response to Berry with an A

Had the same problem one year ago. Got nowhere, even after bringing my iMac to our local Apple Store. The funny thing is, my computer is a mid-2007, 20" screen iMac, not a new one like yours.

I had a real ordeal, with kernal panics, etc., until Apple finally gave me a free OS upgrade (to 10.5.4). Then the problem went away, so I really came to the conclusion that it wasn't hardware related after all.

BTW, the problem spread like a virus to my 2 older computers as well (an "eMac" and an "iBook G4"). Everything cleared up with the upgrade to Leopard.

Here's a snapshot of my computer FWIW:

Model Name: iMac
Model Identifier: iMac7,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.4 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 2 GB
Bus Speed: 800 MHz
Boot ROM Version: IM71.007A.B03
SMC Version (system): 1.20f4
Serial Number (system): W88063T6X86
Hardware UUID: 00000000-0000-1000-8000-001EC214AFBC

NOW, after a year of relative peace, the "spontaneous shutdowns" are starting again. I'm having about 1 or 2 per day.

Sep 3, 2010 10:48 AM in response to Michele Smith2

micheleandray -

Although there were "symptoms" or "results" of kernel panic attacks for my issue (this issue) - this is completely different hardware, completely different OS issue. You should apply your comment to a 20" iMac 2 core duo string/subject.

- - - - - - - - - - - - - -

Loudwater -

I am curious though, to hear if you've still been experiencing the issue since you did the SMC reset. Anything new, different, same?

27-inch / 27" iMac Random Shut down