iMac 27" (Late 2012) Loud Fan and Overheating Issues, causing Hard Drive Failure

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iMac 27" (Late 2012) Loud Fan and Overheating Issues, causing Hard Drive Failure

Hi all,

I'm having some serious overheating issues with my new iMac. Any help to help me solve this problem would be gladly appreciated since it's really beginning to bug me. Here's what's has happened:

I noticed in the first few hours of switching the iMac on that there was a short burst of very loud fan noise. This has been happening about once every two days since and every time I haven't been doing any heavy processing with the system. I've noticed that the main fan will spin, on average, at 1200rpm. Is that normal? The iMac is very well ventilated and sits right next to a window...

I have also boot camped the iMac with a copy of Windows 8 so I could run some fairly power-hungry games. I intentionally purchased a high end iMac (27" display, Intel Core i7 3.4GHz, Nvidia GeForce 680MX Graphics, 1TB Fusion drive) and expected the iMac to run games flawlessly. However, after a few days, I noticed that the CPU and GPU had shot up to a worrying 80°C whenever I ran power-hungry games, with a very loud hissing noise from the fan. After running games for about 10 minutes, the fan will stop hissing, causing the GPU and CPU to increase to 100°C. The iMac then fails and switches off unexpectedly without any warning. After analysing the Windows event logs, I received an event ID 41: The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.

As this occurred about six times whilst I was testing my iMac's performance, I think my hard drive has now begun to fail - sometimes I will hear the hard drive make a click noise, about once every 5 seconds. Sometimes, the clicking noise causes OS X and Windows to run very slowly (even though minimal RAM is being used and nothing too intensive (Safari, Mail etc.) is being processed). Running Repair Disk and Repair Disk Permissions under OS X's recovery mode as well as a repair in chkdsk in Windows suggests that there were no problems with the hard drive. All I can do is wait a while for the clicking noise to stop, and then performance will increase. I have backed up everything externally.

I have also performed a reset of the SMC as well as the PRAM, which hasn't really helped.

Any help will be appreciated. I will gladly provide any extra logs etc. if they're needed.

Thanks so much,

Alex.

iMac (27-inch, Late 2012), OS X Mountain Lion (10.8.2)

Posted on Jan 3, 2013 10:54 PM

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Answer 1

Best reply

mende1

Level 10

93,538 points

Jan 3, 2013 11:12 PM in response to Alex Cummaudo

Alex Cummaudo wrote:

I've noticed that the main fan will spin, on average, at 1200rpm. Is that normal? The iMac is very well ventilated and sits right next to a window...

That's the default fan speed on iMacs, so there isn't any problem with this.

Alex Cummaudo wrote:

I have also boot camped the iMac with a copy of Windows 8 so I could run some fairly power-hungry games. I intentionally purchased a high end iMac (27" display, Intel Core i7 3.4GHz, Nvidia GeForce 680MX Graphics, 1TB Fusion drive) and expected the iMac to run games flawlessly. However, after a few days, I noticed that the CPU and GPU had shot up to a worrying 80°C whenever I ran power-hungry games, with a very loud hissing noise from the fan. After running games for about 10 minutes, the fan will stop hissing, causing the GPU and CPU to increase to 100°C. The iMac then fails and switches off unexpectedly without any warning. After analysing the Windows event logs, I received an event ID 41: The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.

You must know that Boot Camp isn't compatible with Windows 8 and that Apple hasn't released drivers for Windows 8, so it can fail. Install Windows 7 inmediately until Apple launches updated drivers.

As it looks like the hard disk is damaged, I would take the Mac to an Apple Store. It's in warranty, so it should be repaired for free or you should receive a new one

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Answer 2

Jan 9, 2013 12:02 AM in response to mende1

I did notice that upgrading the graphics card drivers manually on Nvidia's website helped a great deal (rather than using Apple's outdated Boot Camp drivers that were not compatible with Windows 8). However, the fan itself will still sometimes fail to kick in when a power-intensive game starts. However I might just steer clear from Windows all together now, that is until Apple releases new Windows 8 drivers.

I've also noticed that the hard drive clicking noise has stopped and it's been a few weeks. Would you still recommend taking it an Apple Store even if its no longer clicking or...?

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Answer 3

mende1

Level 10

93,538 points

Jan 9, 2013 8:19 AM in response to Alex Cummaudo

The fans start when the temperature increases, so it's normal that, when you start playing, the fans start after some minutes, when the temperature has increased

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Answer 4

WZZZ

Level 6

13,226 points

Jan 9, 2013 8:51 AM in response to Alex Cummaudo

I've also noticed that the hard drive clicking noise has stopped and it's been a few weeks. Would you still recommend taking it an Apple Store even if its no longer clicking or...?

I'd bring it back in and let them check it out. Those clicking sounds are not normal, even if they disappeared now.

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Answer 5

Jan 10, 2013 1:57 PM in response to Alex Cummaudo

Thanks for the post. I wondered about the cooling on the iMacs. It see,s they are going to now be as loud as the MacBooks when doing intensive stuff. iMacs are now off my purchase list for certain now. It's like apple wants to run people off from their computers. What fools.

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Answer 6

jackyden

Level 1

0 points

Jun 5, 2013 12:46 AM in response to Alex Cummaudo

Try using Macs Fan Control free app by CrystalIDEA (http://www.crystalidea.com/macs-fan-control) to monitor all fans & temperatures of new iMacs. It runs in Boot Camp for your case

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Answer 7

Jun 5, 2013 7:30 PM in response to jackyden

After taking the iMac to my Apple Store, the in-store diagnostics showed that there were problems with the fan. My iMac was replaced. Thanks all for your ideas though.

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