27-inch / 27" iMac Random Shut down

Im the one who began this post but stopped following with my last on Sept. 29, 2010. Wow, now there's 26 pages!? And people are still reporting some kind of similar issue? Since performaing updating the SMC firmware and power then the managment process:

( unplug power cable and hold iMac power button 5 - 15 seconds )

Since my last post I've not really had any more problems. If peforming some heavy processor work (video or photography editing) my iMac might get a little warmer, but not the jet engine fan effect anymore.

At a very quick glance - I see a lot of people talking about RAM. I really don't think it ever had anything to do with RAM - unless people have seen a difference using lower quality 3rd party RAM? SMC fixed mine.

When I begain this post I had 8 gigs RAM straight from Apple. Mine was the very first model out in late 2009, preordered & still had to wait three weeks. Since then - replaced 8 gigs with 16gigs, 3rd party RAM but quality Crucial memory. Since my last post 2010, and upgrading RAM - I've still not any random shut downs.

I do however, occasionaly get some kind of quick, weird grey screen with some kind of large digitial pixel look at the top of the screen. I just attribute it to the video card starting up or something. But that's been it. I don't know if this all helps or encourages anyone, but I hope so.

SPECS:____________________________________________________________________________

• 27" 2.8 GHz Intel Core i7 / previous 8gig - now 16gig / 1TB hd

• OS: prefious 10.6.3 - currently 10.6.8

• 3 external drives: 1-320gig 800fw / 1-500gig USB 2.0 / 1-TB USB 2.0

(All drives but last - powered from iMac. The third (1tb USB) has it's own power supply)

Alien Quattro wrote:

Yeah, I think there are seperate issues. Many relating to the amount of RAM used... Some related to the type. Good to hear a simple SMC reset resolved your problem. Cheers.

Alien Quattro:

You should read one of my very earlies comments, probably the 2nd page regarding amount of RAM. As my point was then... it's the reason for post now. It would seem that RAM is actually NOT an issue. Maybe quality of RAM might be a question, but not the amount. But at least when this issue begain (with the first revision of the i7 and my post) this issue was not limited to one or any specific amount of RAM amount.

I had the problem with 8gigs and corrected the issue before upgrading RAM with still 8gigs in the iMac. I only upgraded my RAM to 16gigs in the last six months. And what I'm saying now is... even with 16gigs, I'm still not having any issues.

This issue was corrected by applying the newer SMC firmware update at the time, and performing the power management process I just mentioned with the same original configuration I had with the problem. I still perform the power managment process fropm time to time to keep things running smooth with other operations.

Paul -

I hope the process that worked for me - works for you. It's been so long I can't remember all the research I did at the very beginning of this two years ago. I would just say to make sure you check the download section and be sure to have the firmware update. Do the power managment process, do a little rain dance and hope for the best.

If you still have the issue, try to get your "issue"... escalated within tech support. Look at the screen shot I took, I think on the first page. I found it odd then that Apple actually noted the specific problem in the pull down menu when I was setting up a call back with tech support. They may just be able to walk you through with some updated information since I talked with them two years ago.

Last suggestion: If you end up having to call in - ask for Customer Relations. The call director will most likely still ask you what the issue is. You can tell them the root issue is technical in nature, but you need to speak with customer relations about it. Or however... in your words. Be sure to get the case number from the call director before they transfer you. They "will" have created a case number - regardless, and part of the reason they'll be asking for any information. If you don't get the case number from them, get from whomever you last speak with. Apple "ALWAYS" has a case number up in front of whomever you're speaking with, usually, associated with a phone number you provide.

You can be frustrated, that's okay if you are, just tell them - don't act it out. Remain patient, and helpful with customer relastions, not demanding. They "will" help you if you are willing to be patient. Realize you may have to spend some time on the phone, and possibly jump through some hoops. Explain you've researched the issue (if you have). Provide them specific references within the forums. I know I listed off SEVERAL in my original posts. And if in fact Apple is "aware" of any possible "issues" - they'll get you help. This comes from personal knowledge, and as a former CR rep.

Alien Quattro wrote:

I think it varies depending on person. For some (like myself) the amount of RAM does trigger the problem. So, I think it would not be wise to count out what others are experiencing. Glad to hear your problems are resolved. To the ones that haven't been... at least your post triggered a conversation full of troubleshooting ideas.

Alien Quattro:

I guess to some degree you may be right. I've not gone through any posts since mine, Sept. 2010. I realize there are probably other threads/topics based on similar issues, but with different models. At the time I started this one - there was a similar issue brought up in this thread with the 21" iMac, and possible the i5, but had no relevance because of differing models to what this topic was started on.

I admit - I commented again on this topic that I created, based upon the factors for which it was created; specifically for the early 2009, i7, 27" iMac model. Also at the time - there were many other comments about differing memory configurations, just as I'm seeing in the last few pages of the thread.

Although there "may"... be an issue involving memory, I strongly doubt, as I did then, based on info and experience then and the same now, and personally speaking with approx three senior (Tier 2) tech support representatives; there's no strong evidence that says there's an issue with the number/quantity of memory used.

As I've mentioned - I've not looked thoroughly looked through the last 26 pages since I created this topic, so I'm not sure if it's been addressed? There may be a possible issue of RAM "quality," and maybe there's an issue "mixing" of RAM, or RAM brands? I'm not sure of those possibilities, but if there's any question of RAM, I highly doubt it's an issue of quantity.

I will say, I just glanced at a post you wrote just Feb 23rd stating you can confirm 16gig causes shut down. You might be able to make that statement for your own machine, but I beleive it would be erroneous to make such a blanket statement if meant for the entire issue. In fact, making that statement would be incorrect, because I can confirm the opposite... that I have been running 16gig RAM, flawlessly for quite some time in excess of six months, possibly a year, without a random shut down.

As I said...I had 8gigs of RAM, straight from Apple when I ordered from the very first batch of i7, 27" iMacs upon their release in 2009. I had the shut down problem sometime after the first SMC firmware update. Then Apple came out with another firmware update to address the issue, which I applied... then did the power management process (possibly a couple times - I'd have to look back at my own posts here) and since that - I've not had the issue with 8gis nor after upgrading to 16gigs.

So the short of it... whomever might still be having the random shut down issue you may want to look more specific at the model you're using and more closely cross reference any specific topics on Apple forums. The quickest and easiest is: confirm & update your firmware if necessary, and do the power management process, and you can at least cross that off your list.

If this has anything to do with memory, which I doubt... but if it does... my moneys on that it's an issue of memory "quality", or... possibly mixing memory brands/speeds/odd configurations, but "not"..... quantity. And hopefully... as Alien said - this generates more info to possibly resolve someone's issue.

Alien Quattro wrote:

Yeah, there seem to be a lot of topics out there - some with the same model as yours, some not. Cool that yours had nothing to do with the amount of memory. Cheers.

Alien -

I'm confused by one of your previous posts that I recently made reference to. You said 16gigs produce the shut down issue. I ask because (correct me if I'm wrong) it seems your profile info indicates you also have a late 2009 iMac i7. I have the very first released, preordered 2.8ghz Intel Core i7, 1 TB, originally with 8gigs. Your profile info indicates ( if it's current and correct) you're still running 16gigs? I'm running 16gigs fine.

If we have the same config'd machine, logic would dictate it's not a memory issue, at least not with quantity. Possibly a memory "related" but not directly with RAM - something else other than quantity. As I suggested, possibly with quality, inproper speed RAM, or for somehow mismatched, or certain necessary matching slots?

I had the shut down problem with 8gigs of RAM, and the issue was resolved when I still had the same 8gigs of RAM. I upgraded to 16gigs, and still no issue. I did in fact have the random shut down issue. But now - I've had two different quantities of RAM with no power issue, resolved before changing from 8 to 16.

Logic would dictate that with the exact model - it's not a quantity of memory issue - not because mine never had anything to do with the amount of RAM as you said, but because there is no issue with the amount of RAM.

I will say it's may not be an issue directed to, nor exept to 3rd party, because I had the problem straight from Apple, but only after the initial SMC firmware update. If you feel there's something related to RAM, then...

QUESTIONS:

* What type of RAM are you using?,

* What speed?

* Are they all the same speed?

* Exact sticks?

* What types of RAM are other people using?

* What configurations are people using?

* What brand?

* Is your memory seated properly? Have you re-seated it?

* Correct voltage of RAM?

If anything is associated with RAM, there are a numerous other reasons why - other than simply saying, "mine had nothing to do with the amount of memo." Likely not that, but because it has nothing to do with the amount of RAM in the first place.

Ivan Robertovich wrote:

For me, watching console messages has shown that the shutdown happens right after usbmuxb (which I think is an iTunes thing).

I've also got a new issue of kernel panics appearing and it's always com.apple.ioavbfamily

I've tested memory with techtool so much that I know it's not the memory. But I am getting random shutdowns and the culprit in the console right before every one of them is a bunch of garbage about usbmuxd or whatever.

Ivan -

You're exactly spot onto the real, root issue. I would have to go back to when I began this post, but you'll find early on that I had been talking with several senior techs within Apple, and one of them noticed a problem with the system report I emailed him. He saw a serious kernel panic attack!

If you take notice in my early posts - you'll see the extreme amount of periph's I had/have attached. At first the techs were mildly concerned, but all agreed during the trouble shooting process - that even all my periph's were not an issue.

For me, I resolved the issue with the specific information the senior tech's gave me and I followed. It would seem this issue hasn't gone away, and other beliefs of the issue is. I don't know if any of those people who are saying they know what the issue is, but I know I talked directly to several senior techs.

I think I tried to list out at the beginning of this topic out as well as possible, of the information and directions I was told by those sr. tech rep's. All I can say is - that I had the problem with the same configuration machine as I did after I followed the steps provided, and I've not had the issue since, approxiametly 1 1/2 years now. I will say lastly though - I don't recall there ever being an issue with kernel and iTunes.

I don't know what you've done, but look through my posts, specifically. I have not followed up on this thread until just recently because my issue was resolved long ago, at the very beginning. What is that you've done specificall to try to resolve this issue?

What