You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

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

Sep 4, 2012 6:00 AM in response to oilersrock99

Wow Oilersrock -

I think you went through more than I did. I would not have bought a UPS. That's basically telling you it can't function in normal conditions, besides making you spend more money! I would have told them "no".

When I took mine in - I told the gal who was helping me - I wasn't going to pick I up. I was leaving it there for good. I'm sure that's not what convinced them to replace it - but it "is" something I was willing to do. You should NOT have had to buy a UPS!!

Paul G.

Level 1

9 points

Sep 9, 2012 9:50 AM in response to Berry with an A

In a continuation, here's what happened to me this morning:

I was up early and wanted to listen to something. To keep the house quiet, I decided to wear some headphone. I took the headphone jack and went to insert it into the hole in the back of the iMac. My attempt was not precise, but going into the hole... the machine suddenly lost power.

This was the exact same experience as before, but previously it was when the computer was doing an intense process.

So, my iMac might have something electrical going on... or something that is allowing for it to surge and shutdown. I don't know a lot about electricity, but seems like it is just shorting out.

That's just an interesting update.

Sep 9, 2012 10:09 AM in response to Berry with an A

I did tell them no, and said that I shouldn't have to buy something external to make the computer work. That's when they offered to replace the computer straight up for me. I told them I wanted to try it with the UPS just to be sure it wasn't somthing on our end. Issues have still persisted - not nearly at anywhere the same frequencies, but still happening. They ordered it yesterday for me and I should have it in 2-3 weeks.

Sep 9, 2012 11:06 AM in response to oilersrock99

I've been monitoring this thread for a long time, getting the e.mail updates, and I just wanted to chime in with how my Core i7 27" late 2009 iMac issue was solved. It too would reboot for no reason. It only started when I added 16GB of memory [from OWC, their branded memory]. I live in an area that loses power very often, so I have powerful UPSes hooked up to all electronics [TVs, VCRs, Macs, etc]. Some of the outages last 10 seconds, others for hours, so having things hooked up to battery backup means I don't lose data on computers and I don't always have to reset clocks on other electronic devices 🙂

Anyway, the iMac continues to run 10.6 and I didn't want to upgrade to 10.7 [either in this thread or somewhere else, someone partly solved it by putting Lion on their system].

For me what solved it was getting Samsung memory from OWC. It's been a year now with that memory and though the iMac has other issues [the hard drive is always writing as it appears an app running in the background leaks memory badly as 5GB are in use after a reboot and an hour of just having the desktop showing and no non-menubar app running], the rebooting stopped completely. Since the hard drive issue seems software related, I'm going to do a clean install of 10.6 and start installing apps slowly but surely to see what is causing the issue [Activity Monitor usually has Safari Web Content as a "Real Mem" hog, but my problem happens even w/o Safari running and nothing in AM shows a lot of memory in use].

I'm not a big fan of Samsung re: their smartphones, but I will say that using their memory solved my random rebooting issue.

Sep 9, 2012 11:45 AM in response to Vince LaMonica

I've gotten into literal arguments over the raised issue of memory since I started this thread over two years ago. I certainly don't want to see any misinterpretation - that getting Samsung memory is the solution to this issue because it's NOT.

There is however both a hardware and software related issue. Why do you think all the firmware updates. I dont think we've EVER had so many firmware updates, software updates related to hardware with all the Mavs we've had over the last 20 years - than we' had with this iMac.

It's been suspected the type/brand of memory was the issue, the amount has also been suggested. Neither, on their own, are completely true. I personally had this issue with (OEM) Apple memory and I had it without OEM. I had the issue with 8 gigs and 16 gigs RAM.

And me calling it OEM is even a misnomer, just as saying memory hades different brands, because in reality - no matter what name is on the stick - the majority of time it's the same engine under the hood. So anyone reading this thread should know - getting any one particular brand of RAM is not necessarily the solution to this issue, nor the problem.

From personsl experience, working with nothing but Tier 2 tech support over the last two year - the last 4 months of that was directly with a single tech 2 rep, also working with actual Apple engineers; any root issue is not found with the memory, memory brand, nor the amount of RAM, and that's straight from Apple.

I'll say it again - I know one in these forums have figured out a solution, and I dont think Apple has every really figured out where the gremlins are either. Heck thats why there was an initial release delay in the first place of these things, and why I really think I got mine replaced in the first place.

Paul G.

Level 1

9 points

Sep 9, 2012 12:19 PM in response to Berry with an A

First off, my situation was never a sudden "reboot" but a sudden death. With that, I suspected RAM was the issue, but now that the headphone jack made the iMac suddenly turn off... it seems like the logic board is the issue.

There's not a firmware release that will fix this issue and my confidence is a bit blown in the model. It might be the logic board or how electricity and heat move around the entire unit.

Thanks again for sharing with us, Berry.

sbolin

Level 1

8 points

Oct 11, 2012 8:36 AM in response to Berry with an A

Wow, at least I know I'm not alone now with the spontaneously rebooting iMac!

Same problems as most people here: 16GB ram, iMac restarts randomly, making the computer worthless. I've had it to my Apple authorized reseller (no Apple stores in the country I live) 5 or 6 times now. 3 times ago they _said_ they replaced the power supply, 2 times ago they _said_ they replaced the mainboard, but most times they just wipe the HD and reinstall OSX (ML currently, but doesn't matter which 10.x is installed, problem remains). Interestingly, they DID check the RAM, but said even after they switched it out the machine rebooted, so that is when they changed the mainboard (supposedly - they may just be sick of me complaining about the POS iMac, and just did the usual wipe and re-install).

I'll try a few days with 8GB RAM, see if that helps. If not...back to the shop.

Does anyone know how to force Apple to replace the machine? I've had the machine for nearly 3 years, always has troubles, it really is useless for me to use because I often lose data during the restart, so just can't trust to use the machine for anything half way serious. Not sure the process, though - if anyone knows, I'd apprciate it!

Oct 11, 2012 8:59 AM in response to sbolin

FIRST: You can't "force" APple to replace your iMac. It's actually in your warranty that Apple will choose what to do according to any repairs.

If you still have AppleCare on your iMac you need to ask NOW for a replacement. I don't know if that's a necessary requirement, but it sure helps and bolsters your position. But you can't "force" Apple.

I just got mine replaced in the last few months. By Apple's own policiy - they should consider your computer for replacement. THey don't "have" to, but I suggest reading through the last few pages here to see what other people suggested as an approach.

Im the person who started this thread couple years ago. I use my iMac strictly for business, so it "IS" my livlihood. I finally got fed up and demanded a replacement. Unfortunately, if you live in Asia and there are no Apple stores - it's probably going to be tougher. An AASP (authorised service provider) may be able to help you, but it's better if you had an Apple Store.

You need to make SURE you have all your case numbers, repair history, documentation, including purchase receipt. So, I sure hope you kept notes of conversations, and at least all the case numbers related to the issues you've had with the machine.

If you've jumped through all the hoops Apple has put in front of you - TELL THEM. Tell them youv'e already done everything Apple has asked, and a "repair approach" has not worked. And then - like I said... look through what people suggested as an approach. Remain patient and respectful. You can voice your frustration by saying, "I'm extremely frustrated." Just be upfront, but not confrontational.

Since you don't have an Apple Store - see if the AASP is willing to go to bat for you. IF you have an active case number (they get closed after 30 days) have the AASP call up on your behalf on the case and have them let Apple know you've had three repairs already (If you have)

That's all I've got. Good luck!

Leoto

Level 1

0 points

Oct 11, 2012 9:16 AM in response to Berry with an A

I had this exact same problem, and in my case, I found out that there was a short in the PCB on the secondary internal hard drive (Western Digital 1TB Caviar Black). When I removed/replaced the hard drive, the problem went away. Different iMacs with the same symptom may have different causes, but in the case of my iMac, a faulty PCB board on the internal hard drive was the cause.

sbolin

Level 1

8 points

Oct 11, 2012 9:24 AM in response to Berry with an A

Berry with an "A" - thanks very much! In a way, I'm glad to see that I'm not the only one with this problem. I will point the AASP to this thread, and tell them "See, many many others with this problem - replace my machine, please".

Pretty bad problem Apple seems to have with the iMac, sort of worried to get a new one. Funny thing was, in 2009 when I got it they had the yellow screen problem, and I was so releaved that my machine didn't have that...little did I know then!

noni88

Level 1

0 points

Oct 11, 2012 9:33 AM in response to Berry with an A

Hello, i just bought my iMac a week ago. It is a 3.4 Ghz Intel Core i7 Memory 16gb. My computer keeps restarting randomly every 5 times an hour! does anyone know what should i do? I am new with mac and i am not pleased with this.

Oct 11, 2012 9:43 AM in response to Leoto

So @Leoto....

you're saying your iMac was randomly (A) shutting down, or (B) randomly restarting, (C) Black screen like asleep, (D) and/ or over heating?

EDIT: Oh and also... another issue has been an (E) digital artifacting across the entire screen. Large digital looking blocks on white or blue screen.

I find it hard to believe .... that in essence... a hard drive issue.... was causing these kind of symptoms. In fact... at least in my case of nearly three years of trouble shooting all with Tier 2 Tech support (and others I've read) no one ever diagnose a hard drive issue, nor ever even consider it an issue. And I had mine into Apple Store twice and an onsite tech.

So you were experiencing those symptoms I mentioned above?

Leoto

Level 1

0 points

Oct 11, 2012 9:41 AM in response to Berry with an A

Berry,

Every now and then (once every few weeks), the computer would instantly shut down out of the blue as though the power plug had been pulled. Often, it would take a few minutes before I was able to start the computer again.

Then, I had one last shutdown after which I became unable to start the computer. So I opened up the computer and experimented. When I disconnected my secondary hard drive, I was able to turn the computer back on again. When I replaced the hard drive with another working one that I happened to have, the computer turned on, and I never got the random shutdown issue anymore.

As I mentioned before, I don't think similar or identical symptoms necessarily indicate the same cause, but it's just a possibility that might be worthwhile for people to look into if they're having random shutdowns.

Oct 11, 2012 9:41 AM in response to noni88

@noni88

I think Apple has gotten the kinks worked out since most of these issues were with the (older) new iMacs when they first came out. I've not had any issues with my 3.4 i7. I have an upgraded video card, and 16 gigs of RAM.

Your message is kind of vague on what "exactly" is happening and what "exactly" what you've done to investigate it. The issue could be ANY number of things. Dirty power, something you've installed, something you've done in your settings or preferences. And where did you purchase from? An Apple Store?

You have access to free phone tech support with Apple. I suggest IMMEDIATELY one of two things. Call Apple tech support and trouble shoot some things, especially since you don't mention what you've checked yourself, if anything. SECOND: I would probably call where you purchased the iMac, especially if you purchased from an Apple store to see if you can swap it out - IF you want, and if they will. I believe The Apple Store has a 14 day return policy.

SIDE NOTE:

On the note of RAM: I still have the SAME 16 gigs RAM from my previous iMac that was having issues. People have continued to say RAM was / is the cause of this issue - when Tier 2 Apple techs told me themselves - RAM was not an issue. My situation of using my old RAM with no issues kind of supports that theory!

Oct 11, 2012 9:43 AM in response to noni88

noni88: I would take it back and wait for the refresh of the new iMacs. I had a June 2011 iMax that went belly up after I put Lion on it, the hard drive failed it kept freezing up and major video issues. Then they replaced the memory and second hard drive then the logic boad, they said it could be repaired and asked me if I wanted a new one. I said no, I wanted a store credit, so I bought my wife a Macbook Pro and I got a loaded Mac Mini and Display, so far so good no issues with those computers. Take it back and wait in my Opinion.

Berry with an A: I had overheating issues and 2 hard drive failures according to Apple techs, most likely from stopping and restarting the F r i c king thing from the screen freezing. 😉 This all started after Lion, there were slight problems after Snow Lep. last version but got far worse and un-usable after Lion. I also had the same machine as you did and I miss the speed!

27-inch / 27" iMac Random Shut down