Aluminum iMac Random Shutdown

[LittleJoe]

Ive had my 20" 2.4 for a week now and it just randomly shut down on me. It was an instant shutdown. Just browsing the web and watching a video then instantly dead. It happened the day after purchase as well but I didnt think anything of it until now.

I talked to a friend of mine with the same spec'd machine and its happened to him as well today. He actually had his out of the box for a whole 2 hours when it happened to him.

Maybe this is somewhat normal? I dunno. I never had a problem with my MacBook Pro like this, hell not even my pismo.

Hopefully this isnt a sign of things to come.
Has anyone else experienced this?

[rainydays]

How are your temperature readings? It could possibly be overheating.
If not, do a RAM test.

[jesteraver]

It most probably is the ram. Did you change the one that Apple shipped with your mac? If so best thing call up and get them to send a couple new sticks.

[Cave Man]

Happened to me (Mini) with bad RAM. Don't trust the RAM-checking software; mine passed its test. I simply pulled one chip (of two) to find the culprit and sent it back to OWC for replacement. No problems since.

[LittleJoe]

It could very well be RAM, at least I would hope its the ram.
I have installed a 1GB stick of Crucial alongside the apple stick.

It passes all RAM tests. I reseated it for the hell of it. I had the problem before the upgrade and once after... so if it was bad clues would point to the apple stick.

As for my friend his shutdown was on the stock 1GB.

Also the temps are all within normal... though the GPU Diode temp (whatever that is) is at 70C and thats with no video running. Hmmm.

[beaporwoll]

Yeah I have the same problem.
I bought a 20" 2.4 Ghz iMac and bought a 3rd party 1GB RAM to put in it. It passed all the RAM tests and it wasn't overheating.
I'm taking mine to the Apple Store to let the "Geniuses" look at it.
I'll let you know what they say.
Glad I'm not the only one having this problem.

[thinairhead]

I got my 20", 2.0MHz machine on Aug 10. It did the random shutdown many times the first day out of the box. Took it back to Apple Store, the nice folks tried a number of tests but could not reproduce the shutdown. After another day of shutdowns, they gave me a new machine.

The new unit also has random shutdowns, albeit not as frequently.

I'm putting additional RAM in this weekend and will reseat the Apple stick at that time.

I REALLY like the new iMac, but this shutdown behavior is dousing the fun.

Cheers.

[angrygolfer]

I guess LittleJoe never posted what the end result was? I am having the same exact problem.

[gazelleintense]

i've had my 20", 2.0MHz machine about two weeks, so far so good.

[LittleJoe]

I guess LittleJoe never posted what the end result was? I am having the same exact problem.
Thought I was good to go... went a few weeks with no problems... then BAM... it happened again. I walked away from the computer for 5 minutes to come back to a dead machine. Rebooted and everything was fine. Sigh... now I just need to find the time to drag this thing up to the Genius Bar so they can tell me they cant find a problem with it.

[LittleJoe]

Well... before I went in the iMac started freezing crazy style. After reboot id get anywhere from 2 to 10 minutes of use out of it and then everything would freeze other than the cursor. I tried switching ram, swapping slots, an OS reload, nothing worked to fix it. Crashed 5 mins in after the reload. Ran the hardware test and it found no problems.

Took it to the genius bar, and they swapped the machine on the spot for me.

Best customer service ever.

[glenn.hanson]

Mine has been doing the total loss of power random shutdown too. Just for fun I tried another outlet on surge protector and seemed better. Better, as in not as often. I have to wonder if something in that can be causing a random prob. I would think it would affect all the outlets however. And yes I did all the hoops and resets and erase and reinstall and smc fan control widget etc.

Obviously until this problem is recognized by Apple I doubt I will bring it in. I don't need them poking around for a week just to say it worked fine for them. Once they isolate the cause on other macs I am sure they will know just where to go and what to do.

[Marble]

Note that the random freeze with cursor still active is the notorious (and Apple-acknowledged) software issue. If these problems are at all related, consider rolling your iMac Software Update back to 1.0, which has helped some of us who have the problem.

[jf8]

I am experiencing a random shutdown issue. 20" iMac (Mid-2007) with a 2.4GHz Core 2 Duo and a Radeon HD2600 Pro.

I can't seem to find any cause for the failure. I've seen it happen with the original RAM, replacement RAM, and the RAM from my laptop.

The failure does not seem to be related to overheating; I checked the temperatures after the failure and did not see any problems.

The first failure happened within a few days of getting the system. I attributed it to poorly seated RAM (after I tried to check what brand it was but failed,) but it's happened since reseating the memory. It even shut off once while trying to run Apple Hardware Test.

I've left the system running for weeks between shutdown without the system shutting down (although I have yet to get more than 10 days without a freeze.) The most recent freeze, however, occured about an hour after the system was woken up. Before that point, the system had sent all but 10 minutes of the last 14 hours asleep.

I have seen it happen more than once in a short period of time. It happened multiple times when I was trying to install Leopard (I eventually got it to work.) After the first failure, I went back to Tiger and used the system fine for a few days before trying again.

I am going to take the system off of the UPS, and then I am going to call Apple every time it happens from now on.

The UPS has AVR, has only the iMac plugged in to it, and has worked for over six months with a constant load much higher than that of the iMac. The power is fairly clean to begin with; there is no evidence of the failures being correlated with brownouts.

[Tom J]

Damn, Mac's with Bad screens? Mac's that freeze? Mac's that are shutting down? What's next? Exploding iMac's?

I can't remember when Apple has had as many problems with a new product. I've been ready to pull the trigger and buy an iMac but at this point it's just not worth the potential problems. I may wait until the next revision (Jan?) or maybe not at all (I hope not).

It doesn't help that Apple isn't forthcoming about these issues.

I'm kind of surprised the media hasn't picked up on this.

[RumMunkey]

Hmmm... I had the everything-freeze-but-the-mouse AND the random sudden shutoff tonight.

Im on day 2 of my first 14, so I may be taking this unit back.

[jf8]

I suspect that the optical drive in my iMac may have something to do with its problems. I had trouble reinstalling Leopard due to what I thought was a scratched disk, but I tried to burn a DVD earlier and the system shut down...


edit- 30 minutes later, I had another sudden shutdown. Firsrt, I wrote the Leopard disk image to a FireWire hard drive on another machine. next, I was about 15 minutes in to backing up the iMac's hard drive to the FireWire drive, and the Mac shut off.

[Muncher]

Uh oh. So, these problems should show up from when you first start using your imac, right? Right?! :D

Damn, Mac's with Bad screens? Mac's that freeze? Mac's that are shutting down? What's next? Exploding iMac's?

I can't remember when Apple has had as many problems with a new product. I've been ready to pull the trigger and buy an iMac but at this point it's just not worth the potential problems. I may wait until the next revision (Jan?) or maybe not at all (I hope not).

I've heard of an iPhone screen that exploded outwards (while charging).

[jf8]

I've been running Windows Vista for the last week and I've gotten a few freezes, where the system stops responding to input, the internal display shuts off, and the external display shows a black screen - but the fans are still running.

I suspect that the Vista freezes and the OS X shutdowns are the same issue, just with the system fully powering down while OS X is running.

[jkamin73]

ya same thing is happening with me. the weird thing is, i have looked around the forums and a lot of the people with the problem bought their imacs during the third week of august including me. i am going 2 the apple store 2day 2 possibly get a replacement.

[stuff99]

i got my imac the first or 2nd week it came out I believe and this problem just started happening to me


what to do?

[Albal]

At least yours all turn on in the first place.

[stuff99]

has apple addressed this issue yet?

[Nadav]

This has happened to me 3 times. Twice while using the ichat new effect download from the apple site, and once while using microsoft word which just arrived her yesterday. It really pisses me off.

[stuff99]

how long have you had your new iMac?

The whole reason I switched is to avoid this annoyance...and apple phone CSR is only covered for the first 90 days or they force you to buy this apple care crap...

what kind of customer protection is that

[Vagrant Pistol]

Min shut down twice within 2 weeks. I bought it mid October. :confused:

It hasn't happened since though.:cool:

[f1]

I have recently learned that RAM tests are practically useless. I recently upgraded the RAM on my Macbook with third party RAM, and it caused kernal panics as soon as it booted into OS X. Occasionally it would allow me to log into OS X and acutally do stuff for a good half hour or so. During those occasions, I was able to run diagnostics, and the RAM passed. Went back to the reseller had the RAM swapped, no problems since...

[jf8]

I've been running Windows Vista for the last few weeks, and I've still been experiencing crashes. I am guessing that they are all caused by the ATI graphics hardware or driver. With the Boot Camp included drivers (I think they were dated June), the system would occasionally freeze completely in Windows, often while on a black screen (but with a signal still going to my external display.) With the latest Catalyst 7.11 drivers, Windows has reported a few graphics driver crash recoveries (where the screen goes black for half a second, then comes back on as before). The worst was last night, where the graphics driver crashed and recovers about 10 times before the system finally froze altogether.

With the latest drivers in OS X 10.5 and Windows Vista, I was able to use the system for about a week without rebooting before it froze/shut off. This includes anywhere from 1-3 sleep/wakeup cycles a day. In OS X 10.4 and with the original Boot Camp drivers, freezes seemed more frequent.

I suspect that this is either a) a hardware problem or b) a problem in ATI drivers for OS X and Windows. I further suspect that Windows does not respond to the freeze (that is, the computer stays running but doing nothing), while the computer shuts off when in OS X.

[fastone]

I just bought my 20 inch imac 2.0GHZ one week ago from FRY'S electronics in Oxnard, Ca. Right out of the box, after about two hours it just shut down. It has continued to do this at least twice a day, mostly when I'm using imovie to edit my movies. I thought it was the surge protector and bought a new one, but that didn't help. After reading the posts on here, I'll try running some tests with the test software, and maybe taking it in. Without this problem, i make quick, easy, cool looking home videos with it.

[gkarris]

I just bought my 20 inch imac 2.0GHZ one week ago from FRY'S electronics in Oxnard, Ca. Right out of the box, after about two hours it just shut down. It has continued to do this at least twice a day, mostly when I'm using imovie to edit my movies. I thought it was the surge protector and bought a new one, but that didn't help. After reading the posts on here, I'll try running some tests with the test software, and maybe taking it in. Without this problem, i make quick, easy, cool looking home videos with it.


We had this problem at church. I put in a better quality APC Battery Backup and it went away.

I was also going to update to Leopard just in case...

[geissap]

I'm curious to what your guys' console logs show?

If you go to utilites and open up console. And then click on...hmm I'm not on my mac right now...I believe it's called system.log. It's the last .log in the side menu there. Click on that.

Now search for "shut" see if you get any Previous shutdown cause errors?

Also try searching "heat" or "temp" to see if your getting any overtemp errors or anything related to temperature?

[Larry767]

Just wondering if all you guys are contributing to the rather popular discussion topic on Apple's own discussion forum.

Over 5000 views and 123 replies and dozens of people fighting with the same problem being discussed here. Check it out.

http://discussions.apple.com/thread.jspa?threadID=1088454&tstart=0

[Mindflux]

how long have you had your new iMac?

The whole reason I switched is to avoid this annoyance...and apple phone CSR is only covered for the first 90 days or they force you to buy this apple care crap...

what kind of customer protection is that

That's phone support. Not much you can do over the phone for hardware repair anyway. Suck it up.

[8baal]

I purchased a new 20" 2.4 ghz model this February and now all of a sudden in April I experienced the "power plug" shutdown. This was after updating to the new rom version:

Boot ROM Version: IM71.007A.B03

The discussion on the apple board is locked now and I can't reply there.

[8baal]

Just did it again, when trying to add a user in the Accounts section of the System Preferences.

I guess I'll be calling Apple in the morning.

[opihi man]

I recently purchased a refurbished, 20" iMac. After the first week or so, the computer began to spontaneously and randomly reboot/restart.

This is what I've gleaned from reading various online forums and then talking to Apple support:

1. This is a known issue that seems to be especially prevalent in iMac 20" models.

2. Possible causes: faulty logic board; faulty DC power supply inverter cable; faulty added RAM (I replaced original 1GB RAM with 4GB OWC RAM)

3. It's recommended that you first try resetting the SMC, and then if that doesn't help, try resetting the PRAM. Instructions are available online via Apple support, or the tech can walk you through the steps.

4. In my case, the 3rd party RAM is also a potential source of problems. Apple support suggested that I remove the RAM and replace it with the OEM RAM, which I kept. . . then see if I'm still having that problem. If that doesn't work, then it's probably the one of the other two causes listed in the first item above, and I'll need to take it in to the Apple Store to have them fix it. The logic board may require a longer repair time, whereas the power supply can supposedly be fixed pretty quickly.

5. It was suggested that I put the OEM RAM in the computer before taking it in for service, as the use of 3rd party RAM could complicate things for me and possibly raise warranty issues. So best to just not even mention the 3rd party RAM. Because the 20" models are known to have this type of problem, they probably will not question anything.

I'll go ahead and test it with the OEM RAM, and then if that doesn't work, take it in for repair. Will try to do a follow-up post here.

[getmore]

I was having the same random shutdown problem with my refurb 20" 2.4 and was given the option of repair, replacement, or full refund. I was advised that this is a known issue with some iMacs, but they weren't specific about the cause of the problem.

[opihi man]

As a follow-up to my Post #36. . . changing out the 3rd party RAM back to the 1GB OEM RAM didn't solve the problem. I took the iMac in to the Apple Store where the genius stress-tested it. Of course, everything worked fine while there.:rolleyes:

The genius suggested that the problem might be due to unstable power at my house, and recommended that I upgrade my surge protector to a better model/UPS. I bought an APC UPS and tried it out -- still got the random restarts. In fact, they seemed to get worse. Now the Mac would shut down without even rebooting itself. Finally, it got to the stage where it was doing multiple restarts in a row.

Meanwhile, and to add insult to injury, my friend informed me that Apple had just released the new version of the iMac!

The so-far happy ending? I returned the messed-up Mac -- which I had bought as a refurb -- and paid up $200 to get the new, latest 20" model. So far (fingers crossed), it's been working fine.

(One concern for another topic: two different Apple techs told me that 3rd party RAM may degrade the computer over the long-term. Naturally, one would suspect their being biased and giving me a sales pitch to stick with (expensive) Apple memory. But to be honest, I think they really believed what they were saying, as neither one seemed like they were simply being a good soldier for Apple. So now I'm wondering whether to stick with the 3rd party RAM, get better 3rd party RAM, or go with Apple RAM.:confused:)

[maleko]

Just in case anybody thinks that getting the latest system will help - think again.
My system purchased last week has the same symptoms. I got this for my wife to give her a more stable machine than her old PC!
Guess what she is using now (still)?
Thanks for nothing Apple:mad:

[ryanflucas]

Do any of you guys have the 24" iMac 2.8GHZ with Geforce instead of Radeon?

[8baal]

I had the shutdown problem plague me for another week and I got on the phone with AppleCare.

They came across as wanting to be "buddy-buddy" with me and prompt me just to bring it in to the Apple Store where I bought it from and "they'll fix me right up".

My nearest Apple Store (where I purchased it from, no doubt) is over an hour away... and gas prices being less affordable than they have been, I wasn't interested in dropping off the Lemon only to get it fixed and have to come BACK to get it. I kept the box just in case I had a problem with it (behold...!) but Apple told me they don't accept Desktops being shipped in for repair, only laptops. Booooo!!! I didn't think to ask that when I bought the thing, but when I needed repair, Apple was all about telling me what they won't do.

Anyways, I made a big enough stink about it at the store, even told them that I didn't want them to help me with the Migration Assistant - that I had backed it up myself, but I REALLY REALLY wanted out of the Lemon I had purchased and I would pay the difference to get an upgraded model now that the next slew of ultra-fast Core 2 Duos are out.

So now I'm sitting in front of my new 24" 2.8ghz patiently awaiting my 4gb ram upgrade. I ended up selling my old 4gb ram upgrade to a friend with a Dell laptop. The new ones have a bus speed of 800mhz vs last years model of 667mhz.

But the real butt-clencher is that the original problem didn't show it's ugly face for darn near two months after I had got it home and was "happy" with it!

We'll see... we'll see.

Apple needs some serious quality control improvements I'd say. My father was bitten by the G3 iBook "video chip" bug, and a friend of mine went through two Mac Minis before the third one worked fine.

The alternative "mainstream" isn't even an option - I dislike Micro$oft in ways I can't put into words. Guess if this doesn't shape up I'm going to Ubuntu linux and saying "to hell with it".

[co mac noob]

Bought the new 20" a week ago, happened for the first time about 2 hours after taking it out of the box and turning it on. I had just installed Firefox and started transferring my music collection from a shared PC drive. Started it back up, started my file transfer, happened about 15 minutes in. Thought maybe it was related to the large transfer, but then it happened later while I was just browsing the web (looking for info about random iMac crashes). Didn't happen again for a couple days, thought maybe it was just a fluke. Then it started happening again. Thought it might be a heat issue - downloaded Temperature Monitor and kept an eye on the temps, but they were pretty low the next time it crashed. Ran a 45 minute CPU stress test, got the CPU temp to 200F and the power supply to 180F, no problem. Then crashed again an hour later while just browsing the web. Reseated the RAM, still not fixed.

I assume this is a hardware problem, but I'll probably reinstall OSX just so I can say I did (and to wipe my personal info) and take it back to the Apple store. Since I'm within my 14 days, will they just replace it rather than make me leave it with them and let the Geniuses try to reproduce the problem? There doesn't seem to be anything I can do to trigger it, and sometimes it's fine for a couple days, so I'm sure it would behave just fine for them.

[maleko]

Took mine to the "geniuses" (20" 2.66 by the way), and after the initial defensiveness...(What did you put on it? and - never heard of this problem), they gave me a new one because of the 14 day rule. So far the new one hasn't cut out yet.
This has got to be a hardware issue, since it would be more widespread if not. The power supply would be a very likely culprit. If that is the case, repair or replacement are the only viable options. A software update will do nothing.

Good luck to those of you still affected, and I'll report back if it happens again.

[opihi man]

Bought the new 20" a week ago, happened for the first time about 2 hours after taking it out of the box and turning it on. I had just installed Firefox and started transferring my music collection from a shared PC drive. Started it back up, started my file transfer, happened about 15 minutes in. Thought maybe it was related to the large transfer, but then it happened later while I was just browsing the web (looking for info about random iMac crashes). Didn't happen again for a couple days, thought maybe it was just a fluke. Then it started happening again. Thought it might be a heat issue - downloaded Temperature Monitor and kept an eye on the temps, but they were pretty low the next time it crashed. Ran a 45 minute CPU stress test, got the CPU temp to 200F and the power supply to 180F, no problem. Then crashed again an hour later while just browsing the web. Reseated the RAM, still not fixed.

I assume this is a hardware problem, but I'll probably reinstall OSX just so I can say I did (and to wipe my personal info) and take it back to the Apple store. Since I'm within my 14 days, will they just replace it rather than make me leave it with them and let the Geniuses try to reproduce the problem? There doesn't seem to be anything I can do to trigger it, and sometimes it's fine for a couple days, so I'm sure it would behave just fine for them.Can't say for sure, but it seems like the standard troubleshoot would be to go through the tests I mentioned in Post #36, Item #3. Might save you some time if you can go through those either yourself or with phone support, so you can at least get that out of the way even if it doesn't solve anything. If you haven't already and you do get phone support, it seems to help if you get a "case number" from them. That seems to help stop the clock as far as any warranty expirations, since it establishes that you reported the problem at X date.

The first time I took my machine in to the Genius Bar, they stress-tested it for maybe 15 to 20 minutes, while I waited. I'm not sure what stress tests and diagnostics they run vs. what you've tried already. I know at least in part their test consisted of running a whole bunch of processes and windows simultaneously. After that initial run -- where of course nothing happened -- the genius suggested that it probably was an unstable power source on my end, and recommended that I buy a better UPS.

After doing that and still running into problems, they suggested that I might have to bring it in and leave it with them at least overnight, so that they could run the stress tests over a longer period.

While I was at the store waiting for my appointment, though, I was able to crash it myself. . . I had already proposed the swap/upgrade to the just-released newer model, and that pretty much sealed it for me.

Knock on wood, but so far it's been stable. Disconcerting to hear of similar problems occurring after several months of use, though, per other posters here.

[8baal]

Can't say for sure, but it seems like the standard troubleshoot would be to go through the tests I mentioned in Post #36, Item #3. Might save you some time if you can go through those either yourself or with phone support, so you can at least get that out of the way even if it doesn't solve anything. If you haven't already and you do get phone support, it seems to help if you get a "case number" from them. That seems to help stop the clock as far as any warranty expirations, since it establishes that you reported the problem at X date.

- I can't agree more. Get this acknowledged by Apple as soon as possible. Make mentions of the MANY other people reporting this problem on the internet. Apple needs to improve their Q&A process, or at the very least make an effort to proactively replace all the "whatevers" that keep breaking in these machines. Unfortunately, they have a history of being a rather arrogant company.

Disconcerting to hear of similar problems occurring after several months of use, though, per other posters here.

That's the kicker. What is causing this problem is most likely some third-party component that is common between the new ones and the old. That's why I *had* to move out of the 20" to the 24" just to get something completely different. I don't think that's the answer, though. The answer is "Apple, fix this now!"

[co mac noob]

Took mine back yesterday. Didn't have an appt with the Geniuses, but the salesman went in the back and talked to someone and then came out and told me they'd just go ahead and swap it since it it was only 10 days after purchase. I mentioned the forum threads and the reports of the bad power supply and/or cable, and he said "yeah, that's what one of our guys said it probably was".

Brought the new one home and it did the same thing after about an hour. So I'm wondering if I have an issue with the power in my apartment. I've never noticed any lights flickering, or had any problems with my PC or any other appliances. I did try using other outlets on different circuits, but same thing. I'm using a UPS, but it's a pretty basic one that doesn't do any kind of line conditioning. A friend of mine has a more expensive one that does conditioning, so I'm going to leave it with him for a few days and see if it craps out on him.

I'll be a little disappointed if I have to spend $300 on a UPS because the power supply is too sensitive to deal with what's coming out of my walls.

[opihi man]

Took mine back yesterday. Didn't have an appt with the Geniuses, but the salesman went in the back and talked to someone and then came out and told me they'd just go ahead and swap it since it it was only 10 days after purchase. I mentioned the forum threads and the reports of the bad power supply and/or cable, and he said "yeah, that's what one of our guys said it probably was".

Brought the new one home and it did the same thing after about an hour. So I'm wondering if I have an issue with the power in my apartment. I've never noticed any lights flickering, or had any problems with my PC or any other appliances. I did try using other outlets on different circuits, but same thing. I'm using a UPS, but it's a pretty basic one that doesn't do any kind of line conditioning. A friend of mine has a more expensive one that does conditioning, so I'm going to leave it with him for a few days and see if it craps out on him.

I'll be a little disappointed if I have to spend $300 on a UPS because the power supply is too sensitive to deal with what's coming out of my walls.As I mentioned, the Genius initially tried to put the blame on my home power and the (supposedly) inadequate surge protector I was using (an old, APC power strip type). But when the problem continued after purchasing a new APC UPS/surge protector per his advice, he was forced to acknowledge that wasn't the problem. I'd be more PO'd at having to buy the UPS, but I guess I needed a better surge protector, and it was only about $90 (APC ES Series, BE750G, 750VA/450 watts). It seems decent/adequate for a home user.

I also noted to two other Geniuses that a laptop PC/CRT monitor/printer hooked up at the same time to the same (i.e., my original) surge protector didn't display any restart/flickering, etc. problems that might suggest power fluctuation problems. They both said that was a good indication that my home power supply was OK (although they noted that a laptop's power is buffered by its battery). They also said that iMacs should not be especially sensitive to power fluctuations versus other computers.

(Note: Do you live in an area with a lot of new construction going on? The first Genius said that he encounters many power supply problems coming from owners in such areas, because power is constantly being interrupted due to construction -- esp. of the major project, municipal infrastructure type.)

It sounds like a good idea to try running it with your friend's UPS, although I'm doubtful that the problem is with your home power supply, given my own experience. My new iMac is still running OK, but I'm starting to feel like the axe could fall any day now. If it does, I'm gonna do some tough negotiating. You should too. Good luck!

[8baal]

Let 'em have it! Boo to faulty hardware!!

:) good luck

[NowhereMan]

I bought a new 20" 2.4 iMac one week ago and was having reboot and shut down problems, it was completely random. I obviously was very upset and was just about to return it at Best Buy.

I tried resetting the smc, this did nothing. I then installed smcFanControl, I increased the settings a tiny bit and now everything is fine. I did a lot of heavy processing today, converting files, streaming, d/l, etc...and had absolutely no problems!:D

I recommend trying this for anyone having these problems.

I finally switched to a mac from a toshiba laptop running xp and was shocked at how unstable the imac was out of the box. Now that things are running properly I am completely satisfied with this purchase. The machine is beautiful, very fast, and OS X is amazing! Can't wait to upgrade the laptops!:cool::apple:

[co mac noob]

I bought a new 20" 2.4 iMac one week ago and was having reboot and shut down problems, it was completely random. I obviously was very upset and was just about to return it at Best Buy.

I tried resetting the smc, this did nothing. I then installed smcFanControl, I increased the settings a tiny bit and now everything is fine. I did a lot of heavy processing today, converting files, streaming, d/l, etc...and had absolutely no problems!:D

I recommend trying this for anyone having these problems.

I finally switched to a mac from a toshiba laptop running xp and was shocked at how unstable the imac was out of the box. Now that things are running properly I am completely satisfied with this purchase. The machine is beautiful, very fast, and OS X is amazing! Can't wait to upgrade the laptops!:cool::apple:

Hope it works out for you. I tried smcFanControl with no luck. It never seemed to be an overheating issue anyway, as I was monitoring the temps with Temperature Monitor and all of my crashes have been while I was browsing the web and (in a couple of cases) transferring files from my PC over the wireless. I ran a stress test which got my CPU up to 200F and let it run for awhile, and it was fine. So there didn't seem to be a correlation between heavy processing and the shutdowns.

Even it works for you, that kind of seems like a BS workaround. The fans should run fast enough by default to keep the machine from overheating. smcFanControl was designed to keep the laptops cool so they don't burn your crotch.

Let us know how it goes.

[NowhereMan]

I agree that we shouldn't have to install a program in order to properly use our computer.

It didn't seem like my computer had a heating issue either. When I installed fan control I left everything at the "stock" speeds and the temp was always around 30 degrees celsius. I then decided to up the rpm's and everything has been good so far. Hopefully I don't have anymore problems. This whole thing is very frustrating. An official fix should be out by now, it seems like a lot of new imac users are having this problem. I'll let you know if anything changes....

[opihi man]

I agree that we shouldn't have to install a program in order to properly use our computer.

It didn't seem like my computer had a heating issue either. When I installed fan control I left everything at the "stock" speeds and the temp was always around 30 degrees celsius. I then decided to up the rpm's and everything has been good so far. Hopefully I don't have anymore problems. This whole thing is very frustrating. An official fix should be out by now, it seems like a lot of new imac users are having this problem. I'll let you know if anything changes....Thanks for the heads up on the SMC FanControl. Since I'm running OK so far on my new 20" iMac, I may not mess with that yet. But you got me thinking that I should at least be monitoring my temps via TemperatureMonitor. (Sad to think we even should have to do that!)

One question I had about TemperatureMonitor -- the developer mentioned something about not supporting Penryn:

http://www.bresink.com/osx/0TemperatureMonitor/history.html

Can someone please explain what he means? Does TM not work properly for the new iMacs? TIA.

[co mac noob]

Well, it's crashing at my friend's house too. Looks like I got two lemons in a row.

[Leon Kowalski]

Can someone please explain what he means? Does TM not work properly for the new iMacs? TIA.

Sounds like the "CPU Core" temp readouts have been removed, but
"CPU temperature diode" (and/or heatsink?) temps are still reported.

Just install it and see -- the price is right.

LK

[NowhereMan]

I've had 2 reboots since using smcfancontrol. I went 2 days with no problems and got my hopes up.

I had smcfancontrol on but put the fans at the default rpm speed. Since then I had my computer shut down. I tried to turn it back on and it crashed again on the boot screen. It then sounded like it was running, but the screen was off. I ended up having to hold down the power button to make it turn off, then hit it again for it to finally boot up.

I bought this imac from best buy about 9 days ago. They have a 14 day return policy on computers. It's going back tomorrow! Hopefully my next one is okay. Its a pretty big let down for a first time mac user. I bought a mac because I was having shut down problems with my windows xp laptop. :mad:

Good luck to the rest of you.....

[opihi man]

Sounds like the "CPU Core" temp readouts have been removed, but
"CPU temperature diode" (and/or heatsink?) temps are still reported.

Just install it and see -- the price is right.

LKThanks Leon, I appreciate your input. I probably will just install Temperature Monitor and try it, and you're right about the price. I was a little leery: (1) Because of all these problems I've had so far with my iMac, esp. being a Mac newbie; and (2) In another forum I've read about potential crashing problems caused by Hardware Monitor, the "mother" program for Temperature Monitor by the same developer. The latter item didn't sound definitive, but it was of the nature, "crashes stopped when I uninstalled it," and reported by more than one person.

I realize that TM and HM are pretty much two different animals, but all my past problems have kinda made me gun-shy. Right now I'm just happy to have a stable computer.

[NowhereMan]

I was able to return my imac earlier tonight at Best Buy. Unfortunately they did not have my same model in stock. I wanted to stick with the 20" size and had two options. Either upgrade to the $1,499 model or the $1,099. I opted for the more expensive one and got a faster CPU, more memory and a larger HDD. Shouldn't have spent the extra money but I didn't want to come home empty handed.

The employee was shocked that I was having problems with the imac. He said it was his first time hearing anything negative. Although they just got there mac center a few weeks ago and started selling one imac model a couple months back....

So far everything is running great. I'll keep everyone updated. Wish me luck!

[co mac noob]

Just FYI, I took my second one back to the store and had the power supply and internal cable replaced. Everything seems fine now.

[co mac noob]

Just FYI, I took my second one back to the store and had the power supply and internal cable replaced. Everything seems fine now.

Scratch that - two shutdowns in the last three days. Why me?

:(

[opihi man]

Scratch that - two shutdowns in the last three days. Why me?

:(Sorry to hear that. I mentioned these problems that I keep hearing about to the Genius who helped me through mine, and he seemed to kind of dismiss them. I think the gist of his argument was that there were problems in the early iMac models, but that they've been addressed by Apple. He attributed most of the current problems he sees to some type of user-caused error.

He's been pretty upfront and honest with me, but it's hard to believe that there isn't some kind of fundamental glitch in iMacs that's causing all of this. You went through all the "proper" steps, right? Updated software, ran the various checks/tests mentioned in this forum, etc.?

[NowhereMan]

Sorry to hear your still having problems. Id recommend returning your machine if possible...not sure how long you've had it.

I returned my first imac and now have one that has no shut down/reboot problems. But it does have a dead pixel or dust behind the screen. I almost returned it for this but I decided it's better to have a machine that runs solid.

I ran into a guy in my town that was also having problems with his imac rebooting. We don't have a large town and best buy just started selling mac's. I'm shocked that this well known problem isn't getting any attention from apple.:confused:

[vivegannaidoo]

Nowhereman

what are the specs of your new imac? And what are the settings for your smc fancontrol?

[NowhereMan]

Nowhereman

what are the specs of your new imac? And what are the settings for your smc fancontrol?

My new iMac is the 2.66GHz, 320 GB HD, 2 GB ram. I'm not using SMC fan control on my new mac.

[co mac noob]

Just an update/summary:

First iMac was having random shutdowns. Returned it, got another one. Second one was having random shutdowns. Took to the Apple store, had power supply and internal cable replaced. Brought it home, was OK for a few days, then had two shutdowns. Was tired of going to the Apple store, decided to live with it for awhile and see how bad it was going to be. That was a little over 2 months ago, and I haven't had another shutdown since. Really don't know what to think.

[vampyr]

I've had my iMac taken to the Apple store 3 times in 8 months because of power issues and display problems.

First one I got had a display problem... 2nd one was a shutdown that never came back on. 3rd time was a botched repair job on the 2nd time.

Now I was playing WoW... for about 5 minutes into the game, and suddenly everything went dead. I wasn't sure what happened at first... but turned it back on.

I since installed smcfancontrol, as it it seems the top left corner of my iMac is MUCH hotter than I ever remember it being.

I've turned the fans about to about 3000rpm to see how the iMac does. I think Apple needs to put vents on the entire back of the iMac and just blow air directly out the back.

Suddenly I'm having flashbacks of failing xbox 360s.