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

peterwillem Author

Level 1

14 points

Sep 30, 2010 12:17 AM in response to Rojer W. W.

Hi Roger,
I will very soon write a summary of my findings in a new thread, will save readers from struggling thru this one.
The faint tick or popup ,you mentioned, I did not notice.
About the 128 error I found out that it only occurred ( with me) when, after finding the computer black and silent, I restarted it by pressing the power button.The log showed the 128 error at exact the same time as I pressed the button. That gave me the idea that the computer did not actually shutdown but went into a sudden sleep mode, from which it only could be wakened by pressing the power button.
I know the difference is marginal between sudden shutdown and that kind of sleeping mode, but there must be some difference I guess.
Look out for my new thread on this issue.

peterwillem

peterwillem Author

Level 1

14 points

Oct 1, 2010 11:07 AM in response to peterwillem

I have finished the testing of the 2nd set of 2 x 4 G OWC ram and again no problems. After putting back all the 4 x 4 G OWC ram I had a sudden shutdown again within 6 or 7 hours.
I tried working the OSX SL in the 64 bit mode, but than again after 4 o5 hours the same problem.
Now I am working with 2 x 4 G OWC ram and 2 x 2G Apple ram. So far no problems, but it is early days yet.
I just mailed the whole story to OWC and am waiting for their reply.

peter willem

peterwillem Author

Level 1

14 points

Oct 1, 2010 3:28 PM in response to peterwillem

I like to quote OWC reaction to my mail:

Hello,

+OWC has tested the ram in multiple iMacs of this group and the machines work fine with 16 gb of ram.+

XXXXXXXX
+Technical Customer Service Representative+
+Other World Computing, Inc. (OWC)+
+OWC.net, Inc.+

So how come that so many of us have problems with that same ram? What is going on?
Hope that somebody fromApple or OWC van shed some light on this.
I obviously X'ed the name of the person in the mail.
peter willem

JDI

Level 1

0 points

Oct 1, 2010 5:15 PM in response to peterwillem

I have the same problem using Crucial ram.

Oct 1, 2010 9:19 PM in response to peterwillem

Hey everyone. I am experiencing the same problem. I have owned this iMac for about 3 weeks and just experienced my first random shutdown.

My Specs:
2.93GHZ QUAD-CORE INTELCORE I7
16GB 1333MHZ DDR3 SDRAM-4X4GB
2TB SERIAL ATA DRIVE
ATI RADEON HD 5750 1GB GDDR5
8X DOUBLE-LAYER SUPERDRIVE
COUNTRY KIT,IMAC 27-INCH

Does anyone know what is causing this!?

Oct 1, 2010 9:32 PM in response to peterwillem

Here is a link to what the console said. I have no idea what this means, but I saw other people posting this.
http://danielatkins.com/imacshutdown.png

peterwillem Author

Level 1

14 points

Oct 2, 2010 4:37 AM in response to AtkinsStoreFront@aol.com

What brand of ram are you using? Apple, OWC, Crucial or some other?

peter willem

Oct 2, 2010 5:28 AM in response to peterwillem

I am using the ram straight from Apple. They built the entire computer shown in my above post. The Random Shutdown happened 3 more times in the span of 3 hours last night and I just kept it off. Help!

peterwillem Author

Level 1

14 points

Oct 2, 2010 6:18 AM in response to AtkinsStoreFront@aol.com

If this iMac is new from Apple than you still have about a year guarantee and you should contact Apple Care asap.
Meanwhile, if you need your computer and it is not working than take 2 pcs of ram out of the lower slots (the ones closest to the screen. Read the instructions in the manual.
The problem lies most likely with the 16 G ram, and 8G should work without problems.
But you paid for 16G so back to Apple for this.

peter willem

__Tom__

Level 1

0 points

Oct 3, 2010 9:16 AM in response to peterwillem

Peter,

same situation here: Starting with 16 GB RAM I had some sudden shutdowns every day under several conditions.
Following your idea to reduce the RAM to 12 GB did the trick for me. Since then no shutdowns in the last three days.
I conclude, that the iMac 11,3 can't handle with 16 GB RAM.

Thanks so much for this thread!

Tom

Oct 7, 2010 3:39 AM in response to AtkinsStoreFront@aol.com

I am having the same problem and lately seems like I am able to reproduce the shut down but not all the time. I use Aperture 3.0.3, the computer have been shutting down by itself more than 8 times in the last nights while I am syncing photos with Facebook.

__Tom__

Level 1

0 points

Oct 7, 2010 8:41 AM in response to Edmond Leung

Well, in the first days I had the same impression: It seemed to me that Aperture (3.0.3) was the trigger of sudden shutdowns. Heavy computation after migrating my image database to the iMac were interrupted a lot.
Then, the same happened with iTunes after migration of the data. In both cases big parts of the data are on a QNAP NAS, so I suspected that combination not to be fitting.
In the end it turned out for me that sudden shutdowns also occurred using several other software (Mail, Safari, even Finder some times). The conditions varied from high cpu load to nearly idling, from over 60 degrees Celsius (that's 140 F) down to 28 C (82 F), with a lot of apps running at the same time as well as only one app open.

So, I am not able describe any condition to be typical for sudden shutdowns.

After biting the bullet and reducing the RAM to 12 GB one week ago I didn't experience any shutdowns at all. Though I hate to not being able to use full 16 GB of RAM, it seems to me the best deal between effort and benefit.

peterwillem Author

Level 1

14 points

Oct 7, 2010 9:03 AM in response to __Tom__

Tom,
what brand of ram do you use? (OWC, Crucial,....)
You are using 12 G now,you can upgrade that to 14 G. Read the other threads about this problem.

peterwillem

__Tom__

Level 1

0 points

Oct 7, 2010 9:19 AM in response to peterwillem

Peter,

I use OCZ (OCZ3MV13338GK) 4 GB in combination with the original 2x2 GB (Hynix) in my machine.
Thank you for your assistance.

Tom

peterwillem Author

Level 1

14 points

Oct 7, 2010 3:31 PM in response to __Tom__

OK Tom,
that indicates again that the mid 2010 iMac only works well with 16 gig of apple ram and 3rd party ram is out.

peterwillem

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Several sudden shutdowns on new iMac