How to override the fast fan caused by an Incompatible Drive

Written By: codahyder
  • Comments: 5
How to override the fast fan caused by an Incompatible Drive

Difficulty

Moderate

Steps

3

Time Required

No estimate

Introduction

Sometimes replacement hard drives aren't compatible with the iMac temperature sensors, so the fan will go into overdrive.

By removing the control board from your old hard drive, you can trick the iMac into thinking a new hard drive is compatible, keeping it from turning the fan on all the time.

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    • Pretty simple guide here . UNSCREW the logic board PCB from the ORIGINAL hard drive from the iMac 2009/2010/2011+ Hard dive for step 1:

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    • Step 2: is simple. Simply put clear tape or anti static tape on the logic board PCB of the original hard from the iMac . Making sure it wont touch anything, as safety.

    • MAKE SURE YOU PLUG IN only the temperature sensor cable FROM the iMac to the hard drive Logic board we have taped to the iMacs back housing, this is *crucial. This will make the iMac control the fan speed as normal. :)

    I couldn't find any temperature sensor cables in my Late 2011 iMac 27". Either there wasn't enough detail in the instructions above, or these instructions don't apply to this model.

    Tom Gilbert Scott -

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    • and thats it !

    • install hard drive, there is just enough space. Enjoy

    Clever technique! I didn’t think transposing the HDD interface would be a streamline swap. “Didn’t think”being the key words on my part. Well worth the +30 points to the author.

    I wish that I discovered the ifixit web site prior to purchasing OWC’s In-line Digital Thermal Sensor for my mid 2010 27” iMac. Low and behold the In-line Digital Thermal Sensor was NOT the answer to my LCD/CPU hot rod fan issue. My first troubleshooting attempt to determine what was causing the fast fan issue was to return to the original HDD configuration thinking this would restore the CPU fan to perform the the way it was intended. For whatever reasons…. . that didn’t happen…. So swaping out the LCD connections w/and or both HDD and ODD heat sensor connections on the logic board will be the next attempt.

    Thank you codahyder,

    Leonard Zangs -

Conclusion

To reassemble your device, follow these instructions in reverse order.

Author

codahyder

Member since: 29/06/15

257 Reputation

3 comments

Hi! So sorry about that. I did not put in the exact corresponding models which will work with this exact guide (only models WITH temp sensor cable apply* here). Thanks so much for checking it out! I made this a while back, sort of to keep what I had done in archive and to *possibly* help others. For one software fix* I have used a program for Mac called "SSD Fan Control" and it does wonders. For a permanent fix I am not so sure/ there may be kits available through some 3RD party mac stores . Possibly even here ?! That help reroute the internal temp sensor models. Again apologies and best of luck to anyone trying to figure this out. haha :)

Lost account -

I use HDD Fan Control. It uses the temperature read by S.M.A.R.T in the replacement drive. http://www.hddfancontrol.com/

steve -

Can somebody explain how the apple control system works exactly? Why is the above mentioned fix really safe?

Wulf Brandes -