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27-inch / 27" iMac Random Shut down

SPECS:____________________________________________________________________________
• 27" 2.8 GHz Intel Core i7 / 8gig / 1TB
• OS 10.6.3 (about to update to 10.6.4)
• All firmware updates have been applied according to software update
• 3 external drives: 1-320 gig 800fw / 1-TB USB 2.0 / 1-500gig USB 2.0

INFORMATION:____________________________________________________________________

I've been running with this configuration ( 3 extra drives) since approximately December with no issues. Out of the blue... only running Aperture and Safari - my iMac JUST SHUTS off- WITHOUTwarning. It acted as though I was running a MacBook and the battery going dead/asleep. That's how random and sudden it shut down - NO WARNING. I did have the iMac asleep for about three hours before coming back to it to start working again when it shut down, but it should have even been cool.

I only started reading around on the web to see of other incidents after this random shut down this evening, but I can't find anything specific. I've found A LOT of similar things - all seemingly related to "HEAT."

And heat seems to be a certain issue recently - in the last day or two. Today I noticed my top back side to be hot, which isn't uncommon, however, it became so hot I really wasn't able to keep my hand on the top back. I've also noticed A LOT of spinning beach balls, and lots of processor delay! Heat??

There are NO energy saver pref's set to automatically shut it down. The power was and is firmly set. There are no network settings, nor access to the iMac to have it shut down. It is not shared with anyone on the network.

SUMMARY:___________________________________________________________________________

• Today, I grabbed a couple temp / monitor widgets and am trying to watch the data. All components seem to be at/around/below 140 degrees F with ambient air at 77 degrees. I don't know numbers, but that all seems reasonable.
• Going to update to OS 10.6.4 (doubt that's it!!)
• I'm going to run the hardware test from my disc to see if ANYTHING. 8-p
• AND... I'm going to call Apple to set up a case. It's still full under warranty, and I have 2 more years of AppleCare on it. But there's been too many things pointing to hardware to call this a software issue.

I've dodged all the display issues with my iMac, but now.. I'm a bit hacked knowing how much I spent on this thing, with the initial DELAYS I went through, ordering it before it had even been released!

?? QUESTION ??_____________________________________________________________________

So, has anyone else been having this issue, heard of a solution, seen anything on Apple's website of known issues ??

Barry
( Grumbling bout my Mac)

Which one of twelve??, Mac OS X (10.5.6), ever hear Newton?!! ;-) One of those, too!

Posted on Jun 22, 2010 8:59 PM

534 replies

Mar 15, 2012 8:07 AM in response to Ivan Robertovich

Ivan Robertovich wrote:

Barry with an A,

Thanks. I went back to read your posts again, and that's where I wound up on this issue -- that a rocketfish powered USB hub or the SMC/pram is the problem. One difference in our hardware is that I have the i7 after yours (2.93 ghz), but the problem is identical, especially in how it appears to be caused by one of the recent updates.

I reset the SMC, which helped, but I had another shutdown after that.

Like you, i had the same memory and peripherals and stuff all along This machine was rock solid for almost all of 2010, and then, all the sudden near the end of 2010, this started happening with random shutdowns.

I'm not sure if I should reset the SMC again, or do a magic kernel stability dance, but it's **** frustrating because I had a solid, always up machine. Now I have a windows box like thing.

I'm not quite sure what else to do because the problem appears to be bad coding by Apple.

Whoah, Ivan... dude -

if I can provide a little consulation. Yea... sounds just like what my sitch was. I dont' exactly remember when the problem started, but looking back at when I started this string in June... getting my system was a little late, but I think it was in Oct or Nov.

So anyway... I had my system several months with flawless use until that weird little shut down started happening. There was suspicion, too that it was a related heat issue, but I think it was a management issue that caused the heat and kernel panic issues.

To go back to the periph possibility... that's what I'm saying. All the senior techs I talked to were sort of nodding towards thoe at first, but all agreed, even though as many as I had and still have attached, they concluded that it should not be an issue. I even had them calling me back to check on me without my request. I was a little blown away to see Apple showing up on my ID.

Anyway... I don't know how many periph's you have, but I had the following when trouble shooting with tech support and I still have: *800fw hd, *USB hd, *USB hd, *USB hub, *USB printer, *USB scanner, ext speakers, and a second 23" display. That's all I can think of right now.

I believe only one of the USB hard drives has it's own power supply, otherwise they all draw power from the Mac. The USB hub has it's own power, and the scanner is very passive and doesn't require much at all, and I think it's attached to the hub.

All that to say... your sitch sounds just like mine, except the model. Maybe try resetting the SMC again. I know Apple has the directions on line. "How to reset SMC." http://support.apple.com/kb/HT3964 Maybe download and reapply the firmware update - EVEN if you've done it, and then do the SMC reset again afterwards. You can try resetting PRAM and VRAM.

I had to do it a couple times. (reset the SMC) It's also known to help with losing connection if you're using Apple's bluetooth wireless keyboard and/or mouse, which mine has been doing again lately, so I may have to do a SMC reset myself.

Be sure to look at the link (http://support.apple.com/kb/HT3964) and what to do BEFORE the SMC. Things like fast running fans and other things are mentioned for this. That's what happened to me and others, and why early on that there was thought this was a heat issue. From what I got from Sr. tech support - it was a managment issue - hence kernal attacs, heat because fans weren't running properly, and then - poof! In attempts to protect itself - the Mac shuts down.

I would be curious as what you end up doing. Let us know!

Mar 15, 2012 9:27 AM in response to Berry with an A

Thanks for the reply and analysis, Barry!

I do think we're dealing with same issue and I'm glad you got it figured out because I was getting ready to throw my iMac through the window of my local apple store.

I think it was having random shutdowns before I realized what was happening and I was blaming the UPS for them because they were infrequent prior to Halloween/thanksgiving. After then, it became frequent enough that I know something was going wrong and studying what was happening.

I note another thing in the "what to do before resetting SMC" and that is put the Mac to sleep. I can't remember ever putting my Mac to sleep because I use it as a server for various things, not the least of which is iTunes and for certain applescripts that process and email information to me throughout the week (I really hope that sandboxing and mountain lion don't break AppleScript, btw, because that's one of the chief purposes of my Mac).

What I plan to do: 1. put the Mac to sleep to see if it can even do it (like I say, it's never been asleep that I'm aware of). 2. Reset the SMC again.

3. See if any recent firmware reinstalls to SMC code (do you know of the last year firmware or this years from a couple weeks ago changes the SMC?) and run it, if needed, resetting SMC on both sides of the install.

Here's why I became convinced, after beginning to suspect the SMC, it was SMC (and not memory but memory is related because it draw power and thereby makes heat): recently I noticed that if I run handbrake and all eight cores are maxed out, I don't hear the fans kick up the way they used to. That made me think something is screwy in there.

Also, I knew it had to be something beyond the OS because the console messages had no entries about forced shutdown-- rather it would just happen thereby suggesting some low level operation (like SMC).

Mar 15, 2012 4:24 PM in response to Berry with an A

Berry with an "A"

I think we solved it....

For the record, this random shutdowns have nothing to do with memory... Memory affects it because memory draws power (which makes heat) and screws up the corrupt SMC. So everyone who thre away good RAM and is running on less, don't think your safe. The 2.93 Ghz i7 iMac 11,3 sitting right in front of me has 24GB (2x4 and 2x8)

To repeat, the random shutdowns have nothing to do with memory.

it's the SMC --

1. quit all apps;

2. put the mac to sleep and wake up after a bit;

3. zap your PRAM,

4. reset SMC, and

5, zap the PRAM again.

I just ran handbrake (which taxes all eight cores), watched two youtube videos (which taxes the GPU), and had photoshop working on a photo...

I heard something I haven't heard in a long time -- the fans!!! (yes your iMac has fans).

If you run all that stuff, and see the activity monitor showing the cpus all maxed out... after a minute of being pegged out, you should hear the fans and feel very hot air coming out of the upper vent on the back of the iMac

Thanks again Berry!😁

Mar 19, 2012 4:39 AM in response to Berry with an A

Hi,

On Imac 27 3.1GHz Intel Core i5 - Lion 10.7.3 (11D50)

I have the same issue and first, I try determine if a software or hardware issue.

To this, I reboot to bootcamp and the when Windows partition start, I leave the Imac on the desktop screen and I go sleep. Remark that this computer running inside a frozen ambient inside one office room.

In the morning, the Imac stil wait in the same screen on Windows desktop.

I think is possible conclude that this is not a hardware issue and also not a issue caused by a hot ambient.

I do the SMC reset today and will check if this issue go out.

Henrique Simões

Mar 19, 2012 4:41 AM in response to Berry with an A

Hi,

On Imac 27 3.1GHz Intel Core i5 - Lion 10.7.3 (11D50)

I have the same issue and first, I try determine if a software or hardware issue.

In the morning, the Imac stil wait in the same screen on Windows desktop.

I think is possible conclude that this is not a hardware issue and also not a issue caused by a hot ambient.

I do the SMC reset today and will check if this issue go out.

Henrique Simões

Paul G.

Level 1

9 points

Apr 23, 2012 10:45 AM in response to Ivan Robertovich

I was excited about this, but ended up not working for me. Tried and failed in March, but only now following up. Mostly resolved to not sending the RAM back to Critical since it does pass tests... although assume that Samsung RAM would not result in insta-crashes. So, I am just going to hang with 3 sticks of RAM installed... and not too excited about that.

HuDii

Level 1

0 points

May 1, 2012 1:51 PM in response to Ivan Robertovich

Ivan Robertovich wrote:

Berry with an "A"

I think we solved it....

For the record, this random shutdowns have nothing to do with memory... Memory affects it because memory draws power (which makes heat) and screws up the corrupt SMC. So everyone who thre away good RAM and is running on less, don't think your safe. The 2.93 Ghz i7 iMac 11,3 sitting right in front of me has 24GB (2x4 and 2x8)

To repeat, the random shutdowns have nothing to do with memory.

it's the SMC --

1. quit all apps;

2. put the mac to sleep and wake up after a bit;

3. zap your PRAM,

4. reset SMC, and

5, zap the PRAM again.

I just ran handbrake (which taxes all eight cores), watched two youtube videos (which taxes the GPU), and had photoshop working on a photo...

I heard something I haven't heard in a long time -- the fans!!! (yes your iMac has fans).

If you run all that stuff, and see the activity monitor showing the cpus all maxed out... after a minute of being pegged out, you should hear the fans and feel very hot air coming out of the upper vent on the back of the iMac

Thanks again Berry!😁

I have done the exact process listed above multiple times, but my computer still gets random shutdowns. Could it be that there is something physically wrong with my hardware?

Jul 25, 2012 4:08 PM in response to Ivan Robertovich

Were you having random shutdowns, or random restarts? I've been getting random restarts on my 27inch iMac 3.4ghz SSD drive with the 1tb regular HD. It's been happening for months. I have AppleCare, the phone people have been useless. I took it into the store. They first spent 5 days with it and reinstalled the OS. That didn't do anything. I took it back. 5 days later they returned it with the 2 4gb G-Skill sticks out of the machine telling me it was the memory. I took the GSKILL back to the retailer and had them send it to the manufacturer. I bought 2 new 8gb Corsair sticks. Still got random RESTARTS. Took those 2 sticks out and just had the 2 2gb Apple sticks factory sticks in. Still got random RESTARTS. Took it back to the Apple store and they replaced the logic board. Got the computer back this mornign and it randomly restarted on me again this afternoon.

Were your issues random shutdowns or random restarts?

Jul 25, 2012 4:59 PM in response to oilersrock99

Dude... I think I have NOW experienced ALL of the issues that have been associtated with this machine.

When I began this thread (WOW!) TWO years ago - I was definitely experiencing random "shut downs" and that has been the crux of what I've experienced. I don't think it has ever been with memory, but some people swear that's the root of the issue. Since then - I believe I've experienced EVERY issue with these, over heating, shut downs, start ups, black screen, freaky screen start ups, horrible screen perfomances... all except the cracked screen upon arrival issue.

I have, for the last two months, now experienced a somewhat different issue, but documented by others where my iMac seems like it randomly shuts down, always after getting really hot, but doesn't matter what I might be doing when it happens. However... instead of just shutting down like it use to, there is still power being supplied to all the buses. My second display however, loses signal.

I, too have had my iMac to an Apple store, and they were unable to determin ANYTHING. I have done 2 and 1/2 years of trouble shooting. I just recently had my logic board replaced AND my video card. I have reinstalled my OS at least 2 - 3 times and I'm absolutely SICK & TIRED of losing all my information and settings, for weeks on end. This is my business computer, and I cannot function this way.

I've had a lot of issues with video display, and probably why my video card was replaced. When you get to where I'm at - I know all that starts happening is - Apple just starts throwing parts at the problem. I guess they can still replace the hard drive and power supply.... maybe throw some memory at it, but not much else left inside the thing to do to it.

I believe there is something inately wrong with this line. Don't get me wrong - I've been with Apple a long time through thick and thin from when I first started on a 128k or 512k Mac around 1985, and through the dark mid to late 90's. I love the desine, the concept, construction about these, and most everything about Apple, but this thing... there is something just not right within them, and it doesn't seem Apple has figured out what it is even with later revisions/models.

It would seem everyone who's experienced one or another of the issues associated with the 27" i7 has at some point seemed to resolve whatever it is they're experiencing, but something always comes back. Let's blame it on Intel!

I've hinted at a replacement, but I use to work with Customer Relations and I know I've STILL not jumped through ALL the required hoops it takes to get a replacement. And the last I knew about replacements - that process in itself was complicated.

But in short... I believe somewhere over the course of 2 1/2 years, yes, I have also experienced random "restarts" as well. I've lost count of case numbers I have, the last of which I've been working with the same Tier 2 tech support for two months I think? He has also been communicating with actual Apple engineers, but I never gotten the FULL story from anyone.

It seems for my specific situation - I get the line: "It's software, but it's not. It's hardware, but it's not." It seems if you have an issue with one of these things - you're stuck with some gremlin issue. NO ONE seems to know exactly what it is, or what to do.

Bottom line for my situation - I only have AppleCare left until December. I just don't want to be left with a big, shinny paper weight come December. Apple!! Figure it out or replace my Mac!!

Oh yea... lets see if I can stick in some screen shots, so you can see my pain and misery when my issues start acting up, besides 15 to 30 seconds to render a single brush stoke while using ANOTHER Apple product - Aperture. Here ya go.

Freaky screens at start up, screen distortions while working in aperture, or just wiping out part of my work space on Aperture's desktop area. These are just a FEW of the issues I've endured for almost 3 years!

User uploaded file

Jul 25, 2012 5:08 PM in response to oilersrock99

oilersrock99: Frankly I would take it in for the 3rd time to the Apple store as they did the exact same thing to my machine. The main tech I delt with as an ******* and acted as if it was a minor problem, then I finally got a guy that said, we will give you either a new machine or full credit for your machine, which I took the $3500 and basically bought my wife a Macbook Pro and Apple Display along with a Mac Mini for now. What ****** me off I bought a fully loaded iMac, that was maxed out and a speed demon and once I loaded Lion onto it, it turned it into a TURD! Ironically my Mac Mini and Macbook Pros we have have Lion and zero issues, so I think it is a Hardware issue alone with Lion issue causing some of the hardware issues. I just wish Apple will fess up, now I understand this has also happen with older Apple computers that had Lion put on them, so even though they are out of Warr, I would still be ****** as a decent Apple machine could last for 8-10 years before they fired out. I will give them one more shot on an iMac this fall, but I need a 4-8 core machine for video, and thunderbolt. No matter what they had me do or try, the outcome was a silver brick! But one computer fried out in over 10 years isn't bad considering I have had a ton of Apple Products.

Berry: If you don't want it silver brick, I would take it in our send it back till they flipping fix it, usually 3 times. After that it is new machine or in my case I asked for a credit, which I recieved.

There is still something fishy with Lion as at times on my Mac Mini if I drag some thing into the trash I get screen distortion and if I am on Facebook I get a flickering. So I think some of this goes back to hardware and software not working correctly. I got the same song and dance routing which I never got from Apple before. I have been drinking their Kool Aid for some time, but now they are starting to water it down and not giving us the whole picture on what is going down, in my case I was semi-happy with the outcome but I don't have my Ultra-Fast iMac anymore, I have decided to wait till the refresh of these with Mountain Lion and I will cross my fingers this crap doesn't happen again!

Jul 25, 2012 5:26 PM in response to Berry with an A

Well... it seems the forum logged me out while I was editing my last post. Well.. .since it messed up my edit version - you're all stuck with my crappy unedited version.

I like Gandalf's idea. Maybe I should give it a try. Until then... I'll stick those images in that I had already uploaded. Oh well...

Jul 25, 2012 5:36 PM in response to Gandalf The Grey

I may take it in again Gandalf. I received a call last week from the Tier 2 tech rep, but he really say what he wanted me to do next. What hoop to jump through. At this very moment the iMac is not giving me any ..."real" issues, but I know when I start really working on it - I will.

I mean... it's basically stripped of anything REAL I would normally use, so what's gonna happen when I put back on it what I normally need. YEA! YOu know it - ISSUES again!! I mean - look at my screen shots and pics above!! If you have to run a computer completely bare of what you would normally use - why would you use it? It's useless.

And don't talk to me about Lion!! I've refused to put it on ANY of our machines because of what I've directly heard from others - and NOT just rumor forums. I'm skeptical of Mt. Lion this summer, too!! Apple has REALLY missed the mark with it's OS in the last year or two. I feel like we're dealing with MS and Vista!

I may just take my machine into one of the local Apple stores. I just dread lugging 27 inches around in a box bigger than that. At least I have my box to tote it around it. Maybe it's the answer? We'll see.

MichelPM

Level 10

81,306 points

Jul 25, 2012 6:00 PM in response to Berry with an A

Berry,

I readers going to quickly reply to your post, but after finding out that this has been an ongoing issue.

I, believe, all of your issues have been, for the most part, heat related.

One of the things I didn't find in a lot of the threads here, although I haven't read every single thread, is did you ever clean out all of the dust, dirt and lint buildup in your iMac.

I didn't see anyone mention this.

There are intake and exhaust vents that need to be cleaned out.

Macs do suck in dirt, lint and crud from their internal fans.

If the air intakes and exhaust vents are allowed to build up dust and lint and crud, this could escalate much higher temperatures from within your iMac.

You mentioned a 140 degree temp, at some point. This is a fairly high temperature.

You need to completely power down the iMac and unplug everything from the iMac, including the power cable.

You need to find a place to work on your iMac and lay it on something very soft .

You need to get a small electronics vacuum or, if you have a vacuum with seperate hose and attachments, use either a small upholstery brush or crevice attachment and slowly and carefully vacuum out all of the openings, slots, connections and intake/exhaust venting on the iMac.

If you have never done this, I would get some compressed air and from the top vents blow the air down toward the bottom intake vents and re-vacuum the additonal crud from the iMac.

Clearing out all of the vent openings will allow more heat to escape from your iMac and help it to run cooler.

This needs to be done at least every six months or so and at the very least, once a year!

I have never liked how very warm/hot the new iMacs get.

The heat levels in the new iMacs, I believe, slow cook/roast components to failure over a not so long period of time.

Once your iMac is cleaned and dust, dirt and lint and you've plugged everything back in and verified your iMac is running fine, search and install an app called SMC Fan Control. This little app controls the speed of all of the fans in your iMac.

The app never lets the speed of the fans go below Apple's default speeds. So, you can't have the fans run slower than what they are supposed to normally run at.

The app will allow you to increase the fan speeds to allow your iMac's components run cooler and, hopefully, get longer life out of your iMac.

If you install this app, run all of the minimum fan speeds between 200 to 600 rpm faster than their Apple default minimum speeds.

MichelPM

Level 10

81,306 points

Jul 25, 2012 6:17 PM in response to Berry with an A

Berry,

In your second picture, I get this same pattern/artifact at startup, but goes away once the desktop comes up and the login screen appears.

This is the only screen anomaly I get. I run a 2009 27 inch Core2Duo iMac.

From the look of these artifacts, it could be the video card and not the LCD screen, itself.

I've seen these type or screen artifacts before when there is some issue or incompatibility of the OS and installed video card.

Is your iMac still getting hot or very warm?

Maybe the video card doesn't like the heat, either.

I run a lot of video, 3D modeling and graphics apps and don't have the screen artifacts you get once you start working on your iMac.

To check your iMac's different component temps., install an temp. monitoring app called iStat.

Report your iMac's temps. from this app.

Jul 25, 2012 6:44 PM in response to Berry with an A

Berry, I've had much better luch with the Apple store people than with the phone people. The phone guys have been completely useless for me. I managed to talk with the head tech guy at one of my local Apple stores and he was great. Took it in for me last night and worked on it after hours replacing the logic board. I dropped it off at 5pm last night and got the e-mail at 9pm that it was ready for pickup in the morning. I was 100% sure it was the logic board, but I guess I was wrong. Anyways I'm likely going to call him tomorrow and see what the next step is. I would highly suggest going into the store and talking to someone - however, be prepared for mulitple visits. If I go in again it will be my 4th visit. I am assuming you are a photographer (like myself) and this is my work computer also. We have a 15inch MBP that we've been using while this guy has been in the shop and it is such a pain. What I may end up doing is taking it in and then buying a new iMac to use while mine is being worked on, and then returning the new iMac once mine is done being worked on. I can't afford much more downtime. We have a 10 day break in August where we're going away on vacation, so that'll be my last real chance to get into the shop.

27-inch / 27" iMac Random Shut down