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iMac (27-inch, Late 2012) - Fan running constantly after updating to Catalina Software

Hello Apple & Community,


Since I updated my iMac 27inch 2012 model it constantly overheats and fan goes flat out. It never did this before updating and I don't do much on it besides check emails and use internet bowser. Has apple got a fix for this yet?

iMac 27″, macOS 10.15

Posted on Dec 23, 2022 5:05 PM

Reply
5 replies

Jan 28, 2023 4:03 PM in response to Todd0213

Thanks for reply, I'll try resetting the SMC, I do have an iMac 27inch which is a 2012 model and it is also running a lot slower since installing the Catalina Software, the fan is definitely running more often and louder and faster. As I said I hardly use it for videos etc, mainly just emails and surfing websites etc.


Any other suggestions would be appreciated.


Thanks again

Dec 26, 2022 1:06 PM in response to EcoAussie

Greetings EcoAussie,


That's a great question! To confirm, are you noticing a different in temperature or only the fan running fast? If the issue is only with the fan running fast and loud, resetting the SMC is a great step that can help with resolving this issue. You can find the steps for resetting the SMC in the following article. You can also find additional helpful steps in the second article below.


Reset the SMC of your Mac

About fans and fan noise in your Apple product


If you're noticing increased temperature, there are additional steps that can be helpful in isolating this issue and reaching a resolution. Those details are outlined in the following article.


Keep your Mac laptop within acceptable operating temperatures


Have a great day!


Feb 12, 2023 8:19 AM in response to EcoAussie

Hey EcoAussie,


Something you could try just as a test would be loading up your Mac into safe mode. What that does is load only very specific items, and in doing so, it can be used as a way to try and weed out the causes of problems in the normal boot environment, which in your case would be the random restarts and slowness. This could be caused by a multitude of reasons, so this is a great place to start. This page will tell you how to Start up your Mac in safe mode, and when viewing it, be sure to follow the steps within the "Start up your Intel-based Mac in safe mode" section, as that's what applicable for your model of Mac.


Once in safe mode, if the behaviors you noticed, such as the slow launching and random restarts, no longer occur, that likely means that something, potentially third-party software, is causing the behaviors you're seeing. If things appear the same in safe mode as in your normal boot environment, the next thing you'll want to try is to create a test user account and see if it has the same issues. These are both great steps for isolation purposes as it helps to weed out potential causes. The "Add a user" subsection of Set up users, guests, and groups on Mac explains the process and gives you the available options and explains what each one means.


If the same behavior is seen both in safe mode and in a test user account, your next move should be to Get Support directly from Apple for a deeper look.


Take care.


Feb 11, 2023 2:39 PM in response to Lindsay_B.

Hello,


Thank you for response, no it did not help resetting the SMC.


As I have mentioned before I haven't changed anything that I do with MAC, its only since I upgraded to Catalina software that the problems began with MAC, it ran perfect before update.


Problems I now have are:


  1. Computer shuts down and restarts for no reason
  2. It is super slow to start up
  3. Runs a lot slower
  4. Fan runs faster


Is it possible to reinstall MacOS Sierra?


Non of these problems existed when I had Sierra, maybe my IMAC can't handle the new software?


I have hardly used my hard drive, it has 2.51TB available from a total of 3.12TB


I would really appreciate some other ideas here. I am not a computer technician and would love to sort this out.


Thanks and look forward to response.


Best Wishes Peter

iMac (27-inch, Late 2012) - Fan running constantly after updating to Catalina Software

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