Several sudden shutdowns on new iMac

G'day everyone,

I've had my iMac for about two weeks and got this problem as well, glad to find a solution, sad to see the problem in the first place ;-(

I worked as an apple tech a few years ago and saw a similar problem. It took me five weeks of testing to discover that the ram was faulty, the machine always failed while no one was watching, or didn't fail at all. One day I just happened to be watching the ram test when it shut down. Ran a PC test on the ram and confirmed the problem. So when I first saw this happen my immediate thoughts were ram.

I too have OWC ram, and have now changed my configuration to the suggestion posted here. It's a shame that I can't have my 16Gig of ram, but then I'm not sure if I would ever use that much anyway.

I hope Apple are working on a firmware update.

By the way I upgraded from a PowerMac G5 1.6Ghz with 2Gb of ram so I'm lovin' it 😉

Michael

I still don't think it's memory problem. Since my last report of experiencing the shut down nearly 10 times within two nights while I was syncing Facebook photos within Aperture 3.0.2, I switched to Adobe Lightroom 3.2 and I haven't had one shut down. I have not touch the 12GB RAM that I have.

I think and hope that Apple is reading this and probably will be fix with a firmware update.

Edmond you may be right. But I can tell you that I have been using Lightroom 3.0.2 and had the sudden shut downs. Now I have Samsung ram from OWC and I have not had a sudden shutdown in two days. I was getting it several times a day with NU ram which I returned. I also was not getting shut downs with 12 gigs of Nu ram but was with 16.

@ peterwillem - Am I missing a link? What are you resting your case on?

BTW: I switched out two sticks of My OWC 4GB RAM back to the two APPLE 2GB sticks for 12GB. It was ok for about a week an now I have had a few instant shut downs. The click or pop occurred for two of the shut downs. I believe Aperture 3.0.3 was open for most of them, but for at least one shut down, it was only iTunes open. Ido get high heat in the back left quadrant. However, I may still need to swap positions of the 2GB and 4GB. I think the 2GB sticks are nearest the screen.

When I get home from work, I will read the earlier link you posted to, to see if that is your - Ah-Hah - moment.

Thanks for all the good info and keeping the details straight.

This is it. I have had 16 ghz of Samsung Ram from OWC now running for a week with no problems at all. For me this is the answer and the machine is s a joy to use.

i seem to have a similar problem however i have 16GB of (Apple installed) ram in my brand new iMac

G'day again,

Just a quick update, Been running for three weeks and no issues, I have given the machine a flogging encoding HD video (all done in an evening now rather than four days!)

Coping with the heat as well, I'll see how it goes in the middle of summer when it's 40 degrees plus outside.

Please note that this is just my report and status update. Take it as what it is.

It's has been a month since I last posted. I have switched to Lightroom 3.2 for a month and I have only had one shut down in the last 30 days. 90% of the time I use Lightroom 3.2, Safari for web browsing and a little Photoshop CS5. I have not changed any of my RAM configuration which has 2x2GB Apple RAM and 2x4GB of third party RAM.

I highly doubt that Apple is not aware of this problem but I don't think Apple can come out and acknowledge this problem because the cost will be too high (I am surrounded by lawyer friends).

Random problem is tough to pinpoint and fix and I hope/guess if they ever solve it, it will be a stealth firmware/software update fix.

Message was edited by: Edmond Leung

I highly doubt that Apple is not aware of this problem but I don't think Apple can come out and acknowledge this problem because the cost will be too high (I am surrounded by lawyer friends).

Random problem is tough to pinpoint and fix and I hope/guess if they ever solve it, it will be a stealth firmware/software update fix.

I once had a newsgroup provider who would mail all the customers any time there was any kind of problem with the service.

They were always out front, always the first to know and talk about any problem.

As a result, I always completed trusted anything they said, and always assumed that if unless they told me otherwise, everything was going great.

And, I told my friends, as I will do now.

http://newsguy.com/

Going the extra mile to build trust with your customers through honest communication is brilliant business, because it is your happy customers that will build your business for you.

Like everyone else, I'm getting the same sudden system coma. Nothing works apart from rebooting. I installed 16GB of OWC ram six days ago. Yesterday, I started experiencing inexplicable shutdowns.

I run my power through a good UPS and none of the other connected appliances were suffering. I found this post, downgraded one of my 4gb modules to one of Apple's supplied 2gb sticks and all seems to be well.

Apple, give us a solution please or at least manage the issue with more courtesy. We've spent a lot of money on a product that doesn't do exactly what you promised it would.

After eight weeks now the first sudden shutdown under the new RAM setup 2x4 GB + 2x2 GB. Hope that rate doesn't deteriorate!