You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

peterwillem Author

Level 1

14 points

Several sudden shutdowns on new iMac

My new iMac had several sudden shutdowns in the last 30 minutes.
Just normal use, open were mail, safari temp. monitor.
Here is a picture of the log just before crashing.
http://i767.photobucket.com/albums/xx320/mariner4/Schermafbeelding2010-08-29om17 1649.png

Hope someone can make out something.

peterwillem

macbook pro 4,1; iMac 27" i7, Mac OS X (10.6.4)

Posted on Aug 29, 2010 9:36 AM

136 replies

ChoPraTs

Level 1

41 points

Jan 31, 2011 3:00 AM in response to ChoPraTs

Received today 4 new modules of 4 GB CSX RAM. Same problem, after installing, random shutdowns.

So, no defective RAM, sure incompatibility Issues.

With 12 GB, 8 GB (2 modules) or 4 GB (1 module) no problem. With 16 GB, impossible to work.

Waiting a response from the shop for the possibility to change this RAM and get Samsung which does not produce shutdowns according to report several users.

Mambirri

Level 1

0 points

Feb 8, 2011 8:41 AM in response to ChoPraTs

I have been dealing with this behavior for long time too and I have an the following configuration.
Snow Leopard 10.6.6
imac 27" late 09 i7 2.8 Ghz
8 Gb Ram

After trying all possible workarounds I have one that it is working fine so far. The problem seems to be related with the memory is addressed by software in 64 bits. This includes Aperture, Itunes and Safari in y case. When I am using them in 64 bits (default setting) I am seeing this unexpected shutdown/reboot/restart. So far I have been testing them in 32 bits setting and it is working fine (crossing fingers).

If you want to give it a try and provide feedback to others, please do it and if we can confirm that this is a real pattern then lets hope that Apple take a closer look with their nartive applications running in 64 bits.

If you do not know how to switch between 64 to 32 bits try this.
1- Via finder go to Applications folder
2- Select the product you want to change that setting (e.g Aperture, Safari, or iTunes)
3- Right click or "Get Info"
4- Select the check box "Open in 32-bit mode"
5- Re-start the product

If you do not see the check box "Open in 32-bit mode" then your product is native 32 bits.

Well .. good luck and lets see your feedback.

Roberto

peterwillem Author

Level 1

14 points

Feb 8, 2011 11:11 AM in response to Mambirri

@ Mambirri

@ mambirri

imac 27" late 09 i7 2.8 Ghz

You are talking about the late 2009 model iMac, while the shutdown problems and 16 G ram are happening with the later mid 2010 model iMacs. So you have a different problem with the same sympthoms.
peterwillem

macbook pro 4,1; iMac 27" i7; 12 G ram Mac OS X (10.6.4)

ChoPraTs

Level 1

41 points

Feb 13, 2011 8:59 AM in response to peterwillem

As I've explained some weeks ago, I experienced random shutdowns with my new 2010 iMac 27" 2,8 GHZ when I upgraded it to 16 GB of Ram with 4 modules CSX sold by Macnificos.com (Spain).

This shutdowns happened many times when I was surfing the Web. Most of them happened when I visited Marca.com with Firefox, but surely the system could have shutdown while I was carrying out any other task.

There was no shutdowns when I downgraded the iMac to a 4 GB, 8 GB or 12 GB configurations with the same modules. The iMac shutdowns happened only when it was 16 GB.

After installing 4 new CSX modules the last week, my machine continued shutdown randomly.

Finally, I've received 4 new 4GB Samsung modules to replace the CSX RAM this friday, and I haven't experienced more shutdowns since I installed them.

My conlusions are:

1) Only Samsung modules can be used safely to configure the new 2010 iMac 27" with 16 GB of Ram, although modules from other manufacturers can work in certain specific equipment or for some users, but not all.

2) Similar problems on other models of iMac (iMac 24", iMacs from 2009) can don't be related to a Ram problem. The shutdowns happened on this other machines with the same symptoms can be produced by another problem.

3) In many cases, it's possible to use RAM from manufacturers as Kinston, Hynix, CSX, Corsair or OWC in the iMac 27" 2010 but only with configurations with a maximum of 4 GB, 8 GB or 12 GB. With 16 GB configurations, the modules of all this manufacturers can produce or not random shutdowns, althought the modules are provided by Apple when we bought the machine. Apple includes different manufacturer RAM to their iMacs, but probably only those suministrated with Samsung modules can work with 16 GB without shutdowns.

4) Of course, PRAM reset, SMC reset, completly Mac Os reinstall and other similar procedures doesn't solve the problem.

5) Apple don't know how to solve or fix this. Apple support offers changes of power supply, motherboard or complete machine, but no one of these steps solves the problem.

6) Apple isn't informing about this RAM problem, and their users and clients are completely disinformed. Everytime the problem appears on a new machine, its user has to spend a lot of time, perhaps sending its equipment to repair without satisfactory results, until he found the solution explained on this forum.

7) One more time, Apple is not behaving as we would wish. They would have to mention the problem to new buyers or at least to its technical support services so that they do not replace equipment, power supplies and other components without purposes. They would have to propose directly a change of ram memory to Samsung modules while their engineers investigate the problem and find a definitive solution.

8) If you are experiencing this problem, the only solution today is use Samsung RAM or configure the machine with less than 16 GB.

In order to finish, I want to be thankful to Macnificos.com by its amiability and help to fix my problem. They acceded to change my 4 modules of CSX for 4 modules of Samsung and now I can work without problems.

Jul 19, 2011 2:05 PM in response to ChoPraTs

Actually as log as you have Samsung RAM in the "top" slots (the slots closest to the screen), you can run other manufacturer RAM in the bottom slots (towards the rear of the iMac). I've been running in this configuration at the full 16GB RAM for over 6 months now without issue. I didn't have to do anything to the OS or do any kind of weird firmware troubleshooting.

gary23

Level 1

0 points

Aug 26, 2011 5:26 AM in response to peterwillem

Just to let everybody know.. I installed ram from OWC last Thursday.. (16 gigs).. And I havent experienced any slowdown or crashes..

Aug 27, 2012 6:42 AM in response to gary23

Very interesting. Good work, all of you. This should be an illuminating experience in how Apple handles the issue of 3rd party upgrades. Quietly absent, the underlying message is clear... "Buy our pre-installed RAM for 5x the market price for assured compatibility." Similar to the "buy our SSD for compatibility without TRIM and fan issues".

This company owns the hardware and the OS. I doubt the these compatibility issues are/were intentional, however I would not be surprised At All to find that Apple, at some level, was aware of these and many more issues and has intentionally not acted to remedy them. It is part of the Total Control philosophy and also makes their support and development much more streamlined to never have to deal with such variables.

Feb 27, 2013 6:03 AM in response to Ratsandwich

not to detract from the numerous 27-inch owners (you lucky lucky peoples 😉 ) that are suffering with this sudden shutdown issue, but I've had it for MONTHS with a 24-inch Early 2008, 3.06Ghz IC2D model....with only 4GB RAM!

It began doing this random grey screen reboot, without warning, after I switched to Mountain Goat (I mean Lion). Had never seen it before that.

Oddly my old mid 2009 MacBook Pro 13-inch did it as well, no warning, not much running and WHAM! reboot.

drove me nuts! 😢

I replaced the old MBP with the i7 model and have yet to experience it again, but totally clean built my iMac and hadn't had it occur for a while, until yesterday about 13:30.

Looking at my logs I see the following:

26/02/2013 09:22:24.339	com.apple.launchd[1]	* Shutdown logging is enabled. *
26/02/2013 09:22:46.000	kernel[0]	Previous Shutdown Cause: 5
26/02/2013 13:36:03.320	com.apple.launchd[1]	* Shutdown logging is enabled. *
26/02/2013 13:36:26.000	kernel[0]	Previous Shutdown Cause: 5
26/02/2013 13:36:41.512	locationd[44]	locationd was started after an unclean shutdown
26/02/2013 13:36:57.020	shutdown[184]	reboot by _mdnsresponder:
26/02/2013 13:36:57.020	shutdown[184]	SHUTDOWN_TIME: 1361885817 20273
26/02/2013 13:47:55.333	com.apple.launchd[1]	* Shutdown logging is enabled. *
26/02/2013 13:48:15.000	kernel[0]	Previous Shutdown Cause: 5

I only had basic load apps open. Nothing major IMHO, Mail, Safari, Messages, Adium, Skype, Firefox, iTunes

after it reboots it always works fine.

But I have a tendancy to reboot again onto the recovery partition, disk utils and then repair both drive and permissions, before starting work again

...just thought I'd throw my 50pence worth in the mix

Oct 31, 2013 10:26 AM in response to peterwillem

I know this is an old thread but I have a 2010 iMac 21.5" with 2x2GB original RAM and 2x4GB Crucial RAM and have been getting shutdown even while in sleep mode overnight.Have been battling with this for months, eliminating apps etc but there seems to be no patern. Sometimes it shutdoen while playing to the Apple TV and other times while the iMac is in sleep mode over night.

Was it ascertained that it was the non Samsung RAM that was the issue ?

If so, I will go ahead and replace my two 4GB chips with Samsung RAM.

Oct 31, 2013 10:40 AM in response to Airsculpture

As long as you keep the original RAM in the top slots, it should be fine. I've been running that way with 16 GB now for some time without anymore mystery shutdowns.

Oct 31, 2013 11:28 AM in response to Paul B. Duke

Top slots are closest to the screen ? I will check where they are when I get home.

Actually I think it's a 2011 model.

Nov 18, 2013 4:57 AM in response to Paul B. Duke

I still encountered problems with the original modules configured closest to the screen and the Crucial memory in the other two slots. I have now removed the Crucial memory ( despite them having been in the iMac since a few days after purchasing the iMac nearly two years ago ).

I am now running only with the original modules in the machine of 4GB memory and will monitor if there are any crashes.

These crashes have only been happening in the last few months so it must be a combo of the memory and OS version I can only think.

Will see if any crashes. If there are not, I will look to invest in some Samsung modules instead and see how they go.

Where is best to get the original memory chips from, apart from Apple ?

Nov 18, 2013 6:53 AM in response to Airsculpture

http://www.amazon.com/SAMSUNG-10600-SODIMM-LAPTOP-MEMORY/dp/B0067GGPXC/ref=sr_1_ 16?ie=UTF8&qid=1384786095&sr=8-16&keywords=Samsung+pc3-10600

Newegg used to carry it, but it looks as if they are discontinued there.

Nov 18, 2013 7:25 AM in response to Paul B. Duke

Thanks for that, also spotted them in OWC http://eshop.macsales.com/shop/memory/iMac/2011/DDR3_21.5_27

slightly more expensive than your link I admit.

Dec 5, 2013 9:46 AM in response to Paul B. Duke

Deleted

Message was edited by: Airsculpture

Several sudden shutdowns on new iMac