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

Reply
534 replies

May 19, 2011 9:00 PM in response to Berry with an A

I am new here, but that is because all of my Mac products have worked flawlessly until now. I have a 27" i3 iMac (mid 2010) and it worked wonderfully on the 4 GB of RAM that came installed. I bought (it sounds like) similar Mushkin RAM and put in 16 GB like others and as of the day of install it mysteriously shut down that night. It has since done it again. The RAM has only been in for two days.


I have read through every page of this thread and it seems as though the first step is to remove 4 GB and make sure to have matching pairs (including the original Samsung RAM). This really ticks me off, why claim something about a product that appears to be untrue? Has anyone went directly to Apple with this issue, or is this something I should take up with the manufacturer? It sounds as if both have already been done, but neither seems to have satisfactorily resolved the issue?


I am still under the 1 year warranty, and I will check my RAM to see if it is the Hynix(?) chip tomorrow, but if this computer is unable to perform up to it's supposed specifications then I feel as though I was mislead and should be able to return this computer. He11, I am still paying it off 😉.


I am getting no errors and all the hardware checked out fine. It is recognizing all RAM.

May 20, 2011 5:10 PM in response to wmukj

I just received the replacement Mushkin Hynix memory this morning and unfortunately it failed. I installed both memory kits and the computer failed to boot with POST chime.

Then I installed one memory kit into BANK 0/DIMM0 and BANK 0/DIMM1 and left the other two banks empty. With one set I was able to boot and get the POST chime then get as far as the login.

I then got the kernel panic error with the transparent screen to reboot. Next I swapped with the other memory kit (2x4 GB) and the computer wouldn't boot, no POST chime. I also reinstalled the memory to ensure it seated correctly, the normal tech stuff.


After all this I replaced the memory with the original Apple Samsung memory and everything is working fine. I then contact Mushkin who agreed that its possible to have a bad chip on the memory. They're shipping the replacement via advance RMA (last RMA at my expense) but said they will test before shipping.

Mushkin have been great with this whole crappy experience but I'm almost to the point of thinking Apple has some sort of agreement with Samsung and forcing us to purchase from them (Apple) or Samsung.

I'll post again once the new memory gets here, hopefully there's better news. LOL

May 26, 2011 11:10 AM in response to Akitaguy

Well i finally got a hold of mushkin, and we think we might have found my problem. Tyler mentioned that i should try each set (2 sticks) by themselves and see if one set was bad. In the process of removing the ram, I noticed that 1 stick did not say hynix on it. So they are going to send out a new stick. I thought there was something funny when i put it in, the ram stick edge color, 3 of them were green, 1 was brown. The brown one was not hynix. (that probably means absolutely nothing, but thought i would mention it just in case)

Jun 2, 2011 9:30 PM in response to kevinp79

I have a similar problem. I own a i5 27'' with 4 Go from the get go. I haven't used it much apart from browsing and listening to music or watching movies (about once a week since I got it in november 2010), nothing more.


I have been experiencing those weird shut downs for a few month now. After bringing my computer back to the Apple store, they kept it a few days and changed the power supply and called me up so that I come pick my Imac. A few days later, the same problems reoccured a few times.


The usual scenario goes like this: I put my Imac to sleep before I go to bed around midnight, and the next morning when I want to check my emails, there's no response from the computer when I press on the magic mouse or the keyboard.


At least, I see that I am not alone in that situation and that they(Apple) might be able to corner the real problem eventually (hopefully) so that I can stop worrying about this being a bad purchase!


I think I'm just gonna have to bring it back again to the geniuses since I'm no genius myself!


Good luck all!

Jun 3, 2011 4:15 AM in response to MarcoV81

Akitaguy, I would give them a call and see if you can't get a tracking number, just so you can see if they even shipped it out and shipped it to the right address.


MarcoV81, if you are only running 4gb of ram, I'm going to assume that you did not replace the standard ram. It sounds like you might have a seperate issue. The random shutdowns that people are experiencing in this topic happen when they max that ram out at 16gb. Anything less then 16gb normally solves the problem so far.


Just for curiosity, did you replace the ram at some point? I would pull out a stick of ram, and check the type/brand. (If its original, it should be samsung i believe). Have you also ran any ram tests (memtest+)?

Jun 3, 2011 6:16 PM in response to MarcoV81

Got the new replacement memory installed and CROSS my fingers and toes so far so good. If it fails this time then I'm sending the memory straight back to the reseller NCIX and bite the bullet and go with Samsung. I must say though that Mushkin have been straight up when it comes to customer services, I can't fault them on this issue. The whole memory thing is always difficult to troubleshoot. The computer runs perfect but once I installed the 3rd party memory it started with the issues.

So I'll see how this memory pans out in the next few days, I'll run Aperture, Parallels and a game or two and see if it caves and goes south.


MarcoV81 I agree with Shadowhywind sounds like you may have a different issue at hand, have you pulled out the memory and reseated? Also reset the SMC > http://support.apple.com/kb/HT3964 <

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve


If this doesn't resolve your issue Marco V81 then it's a trip back to the Apple store. 😢

Jun 4, 2011 3:30 PM in response to Akitaguy

Good news so far the new replacement memory from Mushkin with the Hynix chips is holding on:


15:24 up 21:39, 2 users, load averages: 1.02 0.71 0.35

iMac-i7:~


I've run Parallels, Aperture 3 and a couple of games, that was last night after installing the memory, no shutdowns🙂


Model Name: iMac

Model Identifier: iMac11,3

Processor Name: Intel Core i7

Processor Speed: 2.93 GHz

Number Of Processors: 1

Total Number Of Cores: 4

L2 Cache (per core): 256 KB

L3 Cache: 8 MB

Memory: 16 GB

Jun 14, 2011 2:52 PM in response to Berry with an A

I purchased RAM from macsales.com, the brand being OWC. I got 16GB, and so far it went almost an entire day without shutting down. I don't wanna jump the gun yet, I'll give it a week and report back here one way or the other, but so far, smooth sailing. I ran all CS5 Suite programs, Parallels, you name it, I through everything I could in there, and so far all's well. So looks like in addition to the Mushkin Hynix RAM, OWC is also good to go. Fingers crossed.

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27-inch / 27" iMac Random Shut down

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