User profile for user: rhythmproject
rhythmproject Author
User level: Level 2
396 points

New iMac is fantastic but...occasionally randomly turns off??

Hey all! Loving my new i7 quad-core iMac. Working amazingly smoothly with Logic, Photoshop, etc. Only problem is...it occasionally just turns off. No shut down process, no noise, no weird images or indicators, just entirely shuts off in the blink of an eye. I've had the iMac for about two weeks now and this has happened 6 times. Fortunately, never during data transfer or when running Logic sessions or when having any Photoshop projects opened, only when using Safari. Anyone else hear of this happening? I'm avoiding booking a genius bar appointment because otherwise it's been perfect. Something I should worry about or is this just a bug? THANK YOU!!!

iMac 27" 2.93 GHz Quad-Core i7 16GB RAM, Mac OS X (10.6.4), LP9.1, iPhone 4, Ableton Live 8

Posted on Sep 24, 2010 7:58 PM

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16 replies
User profile for user: rhythmproject
rhythmproject Author
User level: Level 2
396 points

Sep 25, 2010 10:07 AM in response to peterwillem

Thanks for the feedback everyone. I feared it was the RAM and I am, in fact, using 16GB of RAM from OWC (which seems to be the primary problem-causer based on the other threads I checked out.)

So what do you all suggest I do from here? Take one of the cards out (Move down to 12GB)? Contact OWC and try to return the RAM (try another company)? As always, any advice is much appreciated. Thanks!
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User profile for user: peterwillem
peterwillem
User level: Level 1
14 points

Sep 25, 2010 12:03 PM in response to rhythmproject

I think you can not take out only one 4Gig ram. There is supposed to be two rams (4 Gig each) in a ram bank (2 slots).
So it is either 8 or 16 gig. Unless you can use the original Apple 4Gig ram (2x2) from that came with the iMac. Anyhow 2 pairs in one bank.
And one of the posters (labeck) has been using several brands of ram like: OWC, Crucial and one other I forgot the name. All give the same problem.

peterwillem

Message was edited by: peterwillem
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User profile for user: rhythmproject
rhythmproject Author
User level: Level 2
396 points

Sep 25, 2010 3:22 PM in response to peterwillem

Alright - after reading up on this issue in some other threads and on random sites via google, I've come to the conclusion that it's most likely the _+16GB of all third party RAM+_ that the iMac doesn't get along with.

-I know two other people using 16GB of Mac RAM in i7 iMacs - no issues
-I know plenty of people that use many varieties of third party RAM on all varieties of Macs - OWC, crucial, newegg, etc. on Macbooks, Macbook Pros, iMacs and Mac Pros - and they have no problems. So, yes, Apple applies a warranty to their own RAM but the idea of using third party RAM in general is not the issue. Even Apple geniuses will say there is no problem with installing third party so there's something else going on here.

I took out the 2x4GBs of OWC RAM from the two slots closest to the screen and replaced them with the 2x2GB RAM from Apple that came with the iMac. I have since had no problems. Before I switched them out earlier today it was shutting down on me at least once every half hour. Now it seems as steady as ever. I will report back if my iMac continues to shut down out of nowhere but wanted to let everyone know this fix has worked for me so far. If anyone else has anything else to share, please do 🙂

THANKS!
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User profile for user: peterwillem
peterwillem
User level: Level 1
14 points

Sep 25, 2010 4:20 PM in response to rhythmproject

Quote:
Alright - after reading up on this issue in some other threads and on random sites via google, I've come to the conclusion that it's most likely the 16GB of all third party RAM that the iMac doesn't get along with.




Apple would not have.............nooh ....they would not do such a thing,... would they??? Not even from sales point of view..?

peterwillem

Message was edited by: peterwillem

Message was edited by: peterwillem
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User profile for user: normal1
normal1
User level: Level 1
0 points

Sep 25, 2010 8:29 PM in response to rhythmproject

Hi, Sounds like we have exactly the same problem. My i7 just randomly shuts down for some unknown reason. I've read all I can in the forum reference this problem, and there seems to be a lean towards either 16GB of RAM being the culprit, or using none Apple RAM.
I've ran a number of prolonged tests on my installed RAM, and its past every test so far..
I personally think it could be a heat issue. The top of my iMac gets really warm after a few hours of running. I installed iStat and increased the internal fan speed which dramatically dropped all internal temperatures, and the top of the iMac was only mildly warm after about 30 minutes. The iStat app increased the fan speed from around 980rpm to about 1500rpm.
No shutdowns so far today..
Perhaps Apple might investigate the heat issue with these new iMac's and release a patch that increases the fan speed just enough to keep it a bit cooler. I also think that the top vent is rather small in relation to the size of the enclosure.
There is still no definite answer to this very annoying problem..
Only hope that Apple resolves it sooner than later.
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User profile for user: FristieBlade
FristieBlade
User level: Level 1
0 points

Dec 17, 2010 8:38 AM in response to rhythmproject

Just wanted to add my case to the list, same issue.

Imac i7
16GB of NuRam from OWC
regular power loss

After reading similar threads I suppose it will not hurt to fall back to a 12GB config (2*2GB Apple Original from Samsung and 2*4GB NuRam) although I love to max out the machine since I tend to open up lots of virtual machines at once and they perform much smoother with lots of ram installed.

Does anyone know: the ram from Samsung for sale at OWC, is that EXACTLY the same as the one Apple uses? So would the issue be gone by exchanging my 16GB of NuRam for 16 GB of Samsung at OWC?

Or I might just get my wife an Imac as well and have them both with 12GB without ordering extra ram. That way I would not have unused ram, that would be a shame 😉
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User profile for user: peterwillem
peterwillem
User level: Level 1
14 points

Dec 17, 2010 10:59 AM in response to FristieBlade

I don't know if the Samsung ram provided by Apple is the same as the OWC samsung ram.
But I understand from reading this forum on this problem that for most people the change to OWC samsung ram from other 3rd party ram (like Nu ram) solved their shutdown problem if using 16 G.
But no 100% guarantee!
Try to struggle thru all the posts in several threads about this issue and you will find the conformation of what I am saying.
Safest thing to do is to make your wife happy, and in this case it makes you and your iMac happy as well. So it works both ways. But it will cost you!



peterwillem
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New iMac is fantastic but...occasionally randomly turns off??

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