Shrooblord
Level 1 (0 points)

Q: iMac late 2013 OSX El Capitan - Fans Blazing on Boot

Hello Apple community,

 

I just updated to OS X El Capitan version 10.11.2 and now my Late 2013 21.5-inch iMac (16GB RAM, 3.1 GHz Intel Core i7) is blasting its fans continually as long as it's powered. This behaviour started as soon as the machine rebooted into update mode, updating to OS X El Capitan. Now, whenever the machine is powered - even pre-boot and pre-login! -, the machine's fans are on louder than I've ever heard them and they stay at that level consistently.

 

Activity Monitor reads that only 7.89% CPU is used by the system at maximum and 3.0% by the user, but generally sitting at levels with > 95% CPU idle. 6.87 GB of the 16 GB RAM is in use (Google Chrome) but shutting down all apps does not change the fan behaviour. Energy impact stays at a baseline unless I open an app - then it briefly spikes before returning to almost zero. Disk seems very active though. 4.16 GB read and > 1000 MB written every time I load the tab. Network tab seems active, but by far the majority of data sent is to Chrome, which - again, - when shut down doesn't resolve the problem.

 

I've attempted resetting the SMC and the PRAM but no effect.

 

The fans activate and go up to full power as soon as I press the power button and stay on until the computer has fully powered off. Additionally, while resetting the PRAM, the fans went on when I first turned on the power, then stayed on while holding down the P, R, option and command keys even while the computer was rebooting.

 

I've never heard my computer even use its fans before, save for two instances when I was exporting a lot of audio data from Cubase. Now they're on at what I assume is their top speed and they never go down even an instant until the computer shuts down itself.

 

Basically, as long as the machine has power, it's using the fans at top speed.

 

I'm assuming this can't be very good for my machine.

 

Can you help me with this problem?

Thanks,

Shrooblord

iMac, OS X El Capitan (10.11.2), Late 2013, 16GB RAM, 3.1 GHz i7

Posted on Jan 19, 2016 8:20 AM

by Shrooblord,Solvedanswer
Shrooblord Shrooblord
Level 1 (0 points)
A:

Yes, I tried that already.

 

However, there was definitely something wrong with the SMC. I looked at System Information (in Applications > Utilities) and found that the SMC firmware version was denoted 0.000. That seemed very strange.

 

I looked around on the Apple support website and ended up on this webpage
About EFI and SMC firmware updates for Intel-based Mac computers - Apple Support

where you can download firmware for various Mac models and their SMCs. Look under iMac Late 2013 and under the SMC Version column to get your firmware download.

 

After installing the firmware (this took literally 2 minutes), the fans stopped immediately. I put my ear close to the fans and you can hear them whirring very silently again. So they're back to normal operational parameters! Success!

 

So it seemed somehow during the installation of OS X El Capitan my SMC firmware got wiped, or corrupted, or flushed, or in any case made unusable. Downloading the firmware again from Apple Support was the solution!

 

Thanks for taking time to look into the problem guys,

Shrooblord

Posted on Jan 19, 2016 9:18 AM

Close
Shrooblord

Q: iMac late 2013 OSX El Capitan - Fans Blazing on Boot

  • All replies
  • Helpful answers

  • by Shrooblord,

    Shrooblord Shrooblord Jan 19, 2016 8:43 AM in response to Shrooblord
    Level 1 (0 points)
    Jan 19, 2016 8:43 AM in response to Shrooblord

    I also ran an Apple Hardware Test and it came back with the code PFM001 which denotes an issue with the SMC. It advised me to go to an Apple store to get it fixed. My iMac is still valid for AppleCare warranty, so I guess I could do that.

     

    But before I send my computer away, I'd love to know if you happen to have any tips regarding software-related issues perhaps?

     

    The problem only started when I installed OS X El Capitan 10.11.2 - there wasn't any notice of fans before that time. Would the update *really* have messed up my hardware the instant it began installation? That seems unlikely.

  • by Csound1,Helpful

    Csound1 Csound1 Jan 19, 2016 9:14 AM in response to Shrooblord
    Level 9 (50,439 points)
    Desktops
    Jan 19, 2016 9:14 AM in response to Shrooblord

    Reset the SMC

     

     

    To reset the SMC:

     

    1. Shut down the computer.
    2. Disconnect the MagSafe power adapter from the computer if it's connected.
    3. Remove the battery.
    4. Press and hold the power button for five seconds.
    5. Release the power button.
    6. Reconnect the battery and MagSafe power adapter.
    7. Press the power button to turn on the computer.

  • by Recycled Hoosier,Helpful

    Recycled Hoosier Recycled Hoosier Jan 19, 2016 9:19 AM in response to Csound1
    Level 1 (51 points)
    Jan 19, 2016 9:19 AM in response to Csound1

    OP stated that it's an iMac, so it doesn't have Magsafe power or a removable battery...

    =====

    iMac SMC and PRAM reset

     

    iMac SMC and PRAM reset

    rkaufmann87
    By rkaufmann87

     

    Folsom, California

    Level 9 (54,910 points)

    Version 2

    46622 Views

    Last Modified: May 16, 2014 12:16 PM

    SMC RESET

     

    • Shut down the computer.
    • Unplug the computer's power cord from both the wall and computer.
    • Wait 15 seconds.
    • Attach the computers power cable.
    • Wait another 5 seconds and press the power button to turn on the computer.

     

    PRAM RESET

    • Shut down the computer.
    • Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
    • Turn on the computer.
    • Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
    • Hold the keys down until the computer restarts and you hear the startup sound for the second time.
    • Release the keys.

     

    ========

     

    I always wait for the third reboot and 'chime' sound before releasing the keys when doing a PRAM reset.

    It's usually noticeably louder than the first or second chime sound, because I rarely have the volume set full-on.

    To me the increased volume is one indication that the reset was successful.

  • by Shrooblord,Solvedanswer

    Shrooblord Shrooblord Jan 19, 2016 9:18 AM in response to Csound1
    Level 1 (0 points)
    Jan 19, 2016 9:18 AM in response to Csound1

    Yes, I tried that already.

     

    However, there was definitely something wrong with the SMC. I looked at System Information (in Applications > Utilities) and found that the SMC firmware version was denoted 0.000. That seemed very strange.

     

    I looked around on the Apple support website and ended up on this webpage
    About EFI and SMC firmware updates for Intel-based Mac computers - Apple Support

    where you can download firmware for various Mac models and their SMCs. Look under iMac Late 2013 and under the SMC Version column to get your firmware download.

     

    After installing the firmware (this took literally 2 minutes), the fans stopped immediately. I put my ear close to the fans and you can hear them whirring very silently again. So they're back to normal operational parameters! Success!

     

    So it seemed somehow during the installation of OS X El Capitan my SMC firmware got wiped, or corrupted, or flushed, or in any case made unusable. Downloading the firmware again from Apple Support was the solution!

     

    Thanks for taking time to look into the problem guys,

    Shrooblord

  • by Csound1,

    Csound1 Csound1 Jan 19, 2016 10:12 AM in response to Recycled Hoosier
    Level 9 (50,439 points)
    Desktops
    Jan 19, 2016 10:12 AM in response to Recycled Hoosier

    The OP needs an SMC reset, what does resetting the PRAM have to do with that?

  • by Recycled Hoosier,

    Recycled Hoosier Recycled Hoosier Jan 20, 2016 9:55 PM in response to Csound1
    Level 1 (51 points)
    Jan 20, 2016 9:55 PM in response to Csound1

    Precisely as much as posting the SMC reset instructions for a battery-powered Mac in the iMac forum, Csound1. I was in a hurry and both instructions were on rkaufmann87's  page. Please report this incident to the hosts and have them banish me from the Apple Support Communities for spamming the forums with misinformation. I don't ever want to repeat my terrible mistake by attempting to help someone else.

  • by Csound1,

    Csound1 Csound1 Jan 21, 2016 6:12 AM in response to Recycled Hoosier
    Level 9 (50,439 points)
    Desktops
    Jan 21, 2016 6:12 AM in response to Recycled Hoosier

    Don't tell me what I should do, concentrate on what you should do.

  • by clodo9,

    clodo9 clodo9 Jan 21, 2016 6:26 AM in response to Recycled Hoosier
    Level 2 (194 points)
    Jan 21, 2016 6:26 AM in response to Recycled Hoosier

    I thought rkaufmann's P.S. " i always wait for the third reboot and "chime" sound before releasing the keys when doing a PRAM reset " was a nice "tip" ! 

    Nice posts throughout, Recyc', hope you stick around and don't mean it when you write : "I don't ever want to repeat my terrible mistake by attempting to help someone else"...

    P.S.: liked " Precisely as much as posting the SMC reset instructions for a battery-powered Mac in the iMac forum " 

  • by clodo9,

    clodo9 clodo9 Jan 21, 2016 6:27 AM in response to Recycled Hoosier
    Level 2 (194 points)
    Jan 21, 2016 6:27 AM in response to Recycled Hoosier

    I thought rkaufmann's P.S. " i always wait for the third reboot and "chime" sound before releasing the keys when doing a PRAM reset " was a nice "tip" ! 

    Nice posts throughout, Recyc', hope you stick around and don't mean it when you write : "I don't ever want to repeat my terrible mistake by attempting to help someone else"...

    P.S.: liked " Precisely as much as posting the SMC reset instructions for a battery-powered Mac in the iMac forum " 

  • by Csound1,

    Csound1 Csound1 Jan 21, 2016 6:57 AM in response to Shrooblord
    Level 9 (50,439 points)
    Desktops
    Jan 21, 2016 6:57 AM in response to Shrooblord

    Glad to see that my suggestion helped you solve the issue.