Out of control fan iMac 27” 5K (A2115)

[Nome_man]

I have a base model 2019 27” iMac (A2115) upgraded to 40MB RAM, but otherwise not messed with. Lately the fan has been running loudly non-stop. I downloaded the Mac Fan Control app to check the fan speed and CPU temp, and the fan is running at like 3600RPM non-stop, but the CPU temp only ever peaks at like 50C. The fan speed is well outside the throttled limit of 2700RPM that the computer is supposed to limit it to.

I have tried resetting the SMC about 100 times and it never works, so the simple solution is unfortunately off the table. Ran diagnostics and returned an error code of PPF003, which apparently means “fan test failed (low speed)”. Called Apple, and their only solution is to take it to an Apple Store. But there are two issues: (1) of course, it just went out of warranty, and (2) I live in rural Alaska and there isn’t an Apple Store closer than a two hour jet ride. Apple offers no mail-in service for desktops apparently either. I did call a certified service store and they said one of the temperature sensors may have failed. Again, bring it in. Again, same issue that I cannot.

So my questions are:

1. Has anyone else had this issue and solved it?
2. Has anyone else replaced the fan in their A2115? Do you think this might solve the issue regardless of “thermal sensors”?
3. Where are the “thermal sensors” on this model and can they even be replaced? (I’ve Googled until my eyes are crossed and found nothing...)
4. If I am going to crack this thing open anyway, what upgrades should I consider while in there? (Swap the fusion drive for SSD? Add a PCIe SSD?)

Thank you for ANY thoughts you can offer on this. Living in a remote place definitely has it’s benefits, but when it comes to dealing with Apple issues, not so much...

Nome_man

 

[Cory Cooper]

Hello and welcome.

It sounds like there is a hardware issue with the fan and/or sensor. I believe the sensors are actually part of the logic board in the recent models, and aren't individually replacaceable. The fan can be replaced however.

Depending on how long ago the warranty expired, Apple sometimes will still cover it. iMacs aren't officially user-serviceable, and other internal components can easily be damaged when repairing them without the proper ESD precautions and training. The recent models are more difficult due to the adhesive used to secure the display.

iMac Intel 27" Retina 5K Display 2019 Repair

I feel for you, as your are in a tough spot and location. Let us know your thoughts.

C