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

Satoneko

Level 1

15 points

Feb 25, 2011 2:19 AM in response to geo_head

I think Apple’s thought process is this: because RAMs are “peripherals” like your external HDD or printer, it’s not their business if the Mac goes crazy when the user puts in incompatible RAMs. Apple is not obligated to fix your iMac just so a particular peripheral part/device would work properly.

Now, I do understand this stance. Although I do feel it is more efficient and elegant if they’ve told us to just change the RAM, instead of going through the ritual of fixing the power supply unit, motherboard, and maybe replacing the entire computer. For those of us who use the iMac for work, the downtime during repair and the worries about loosing files are extremely frustrating.

I think there is some legal bind or corporate concern that prevents Apple from talking about the RAM, and they seem to be relying on these forums to get the word around. All people have to do is to search “iMac 2010 random shutdown,” and these threads in the Apple Support Discussion come to the top. Still it’s not convenient for people who are not good with search engines and for non-English speakers.

Feb 25, 2011 2:34 AM in response to geo_head

TO APPLE - this is EXTRAORDINARILY frustrating - you should do better.

If you want to tell/inform Apple about your problem and or tell them what you think about it you better use this link:

http://www.apple.com/feedback/

Officialy Apple does not read these threads/posts.

peterwillem

Feb 25, 2011 3:02 AM in response to Satoneko

@Satoneko

I think Apple’s thought process is this: because RAMs are “peripherals” like your external HDD or >printer, it’s not their business if the Mac goes crazy when the user puts in incompatible RAMs. Apple >is not obligated to fix your iMac just so a particular peripheral part/device would work properly.

Basically I think you are right about that, but Apple has a name to keep up. They advertise that their iMac can work with 16 G ram. They even show you how to add/change ram . They never say that you have to use a specific brand of ram, they leave that open. So when it turns out that , when using 16 G of various brands except Samsungs, their machine becomes unstable they should work and look for a
solution. They owe it to their customers. And I think it is very short sighted if they just ignore these problems, of which unofficially they definitely are aware of.
Personally I think they are looking into this, but question is: is their a realistic solution ?

peterwillem

Jeff Donald

Level 8

44,784 points

Feb 25, 2011 1:46 PM in response to peterwillem

Except there are other brands that are working and not just Samsung. I've been reporting for 2 1/2 months that the OWC brand Ram works fine in the 16GB config. An earlier poster in this thread stated that OWC confirmed to him that they "tweaked" their brand back in December. I've also read recently on other discussion forums, that other brands are now "tweaking" their ram to work.

toolman

Level 2

381 points

Feb 25, 2011 1:50 PM in response to Jeff Donald

Not sure it's a ram problem, at least not for me. I purchased new samsung ram from OWC, installed it yesterday and today had another random shut down. I now have 12gb of samsung ram installed that all tests good with both apple hardware test and techtool but still having random shut downs.

pedro3178

Level 2

234 points

Feb 25, 2011 1:59 PM in response to toolman

That's strange, I think you are the first to say they take it under 16G and have problems? Or have I drank to much tonight? Lol. RAM can be faulty but it seems anyone that takes the iMac to 16G gets random problems unless OEM RAM installed, you are correct to say it's not the RAM as it will work fine if it's not taken to 16G, strange!!

Feb 25, 2011 3:15 PM in response to Jeff Donald

@ Jeff Donald

Except there are other brands that are working and not just Samsung. I've been reporting for 2 1/2 >months that the OWC brand Ram works fine in the 16GB config.

I have read several posts in the threads on this forum that said to have the 16 G shutdown problems within the last 2,5 months using recently bought OWC ram.

I've also read recently on other discussion forums, that other brands are now "tweaking" their ram to >work.

What forums are these?

peterwillem

Tank9

Level 1

0 points

Feb 25, 2011 3:51 PM in response to Berry with an A

Get 16gb Mushkin 976647A or 976647. Make sure you install them correctly.

Here was my experience and review on NewEgg, although I bought the ram directly from Mushkin.

http://www.newegg.com/Product/Product.aspx?Item=N82E16820226167&cmre=mushkin_ddr3_1333_204-_-20-226-167--Product

Good luck!

Jeff Donald

Level 8

44,784 points

Feb 25, 2011 4:03 PM in response to toolman

@toolman

I agree, your the first person that I know of that has had an issue with 16GB of Samsung ram. Your issue might very well be power supply, software etc. I'd call Apple support while you're under warrant and move toward getting your issues resolved.

Jeff Donald

Level 8

44,784 points

Feb 25, 2011 4:06 PM in response to peterwillem

@peterwillem

I've read the same posts, but the posters are not saying when they purchased the ram. If they contact OWC they'll send them the tweaked RAM.

toolman

Level 2

381 points

Feb 25, 2011 4:49 PM in response to Jeff Donald

I don't have 16gb only 12. I have 2- 2gb and 2- 4gb sticks of samsung ram installed. I have been on the phone with Apple 8 or 10 times now and we have gone thru a laundry list of items they wanted me to try. The last and final thing they want me to do is re install the OS. I'm doing that tonight. I hope that does it but I'm not holding my breath.

Message was edited by: toolman

Feb 25, 2011 6:58 PM in response to Berry with an A

As Tank 9 indicated, buy Mushkin 976647A (2 x 8GB). Granted, I've only had the 16GB of ram installed for less than a week but, my system has been stable with no shut-down issues. I run Lightroom in a dual-screen setup with a 27" Cinema Display and while temps do rise up as high as 60 degrees celsius - I haven't seen any slow downs etc . . .

If something changes, I'll post an update.

Regards,

Tony

Feb 25, 2011 7:05 PM in response to Berry with an A

Does anyone know where I can pick up 16GB of Samsung RAM in the UK? Having a nightmare finding the correct part number and a supplier. Thanks

pedro3178

Level 2

234 points

Feb 25, 2011 11:56 PM in response to Chris Mearing

Thats going to be hard to get in the UK and if you do happen to find it it is going to cost you £££££
I have used and installed RAM from a company called global memory on ebay, they are UK based and i have never had a problem with their RAM, now with regards to the 16G i really don't know as i only have 8G installed, but just email them and ask, you should NOT! have to buy OEM RAM

Feb 26, 2011 2:23 AM in response to Tank9

@Tank9

Here was my experience and review on NewEgg, although I bought the ram directly from Mushkin.

I read your review and some of the others as well. It is not clear to me if you are using the 2x4 Mushkin ram or 2 x (2 x4 G) ?
The others on that review, who do not have the problems , are all using less than 16 G. At least that is what they write.

peterwillem

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27-inch / 27" iMac Random Shut down