Mac Mini 2010 fans running at 6000RPM Thermo Sensors?

Hi,
First post here, thanks for any help you guys can provide.

I am looking for some advice, and thereafter maybe a repair to my Mid 2010 Mac Mini (with optical drive).

I have what looks to be a very common complaint here the fan runs at full speed (6000RPM) all the time. In my research I have seen that this is often caused by one of the thermo sensors failing. My question's are, is there a way you guys know of pinpointing which of the three thermo sensors are faulty? And I downloaded a third party app to temporarily manually override the ran speed, just out of curiosity. But this was unable to change the fan speed. Does this point to the fault not being a sensor issue, or is this consistent?

Thanks in advance for any help you can provide.
Chris

chrisyaxley said:

In my research I have seen that this is often caused by one of the thermo sensors failing. My question's are, is there a way you guys know of pinpointing which of the three thermo sensors are faulty?

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If in your research you've found that this fan issue can be cause by bad sensors (which makes sense when a temp sensor goes bad)...then it could possibily be a bad fan sensor.

As far as being able to detect which thermo sensor is bad (if a bad thermo sensor is the issue). If you were able to determine which thermo sensor it is...what then will you be able to do about it? My guess is a thermo sensor is very small...and will most likely be soldered to the logic board & be very difficult for the average computer user to replace themselves (assuming the correct replacement sensor can be found & purchased).

I also wanted to mention that I had an older MacBook Pro that had high fan issues like you describe...and it wasn't bad thermo sensor related...it was a bad fan (which Apple replaced & all was good).

Finally...the high fan speed could be a software issue.

chrisyaxley said:

And I downloaded a third party app to temporarily manually override the ran speed, just out of curiosity. But this was unable to change the fan speed. Does this point to the fault not being a sensor issue, or is this consistent?

Click to expand...

I think a lot of times these apps are only successful at speeding up the fan...not slowing it down.

HTH,

- Nick

Hi Nick,
Thanks for your reply.
The three thermo sensors are attached to the logic board at the end of short cables via the three marked connectors on this image from the service manual. I believe one is HDD temp, one is for the optical drive & there over is the ambient temp.

I think the fan itself doesn't have a sensor, and it just uses these three to decide when to increase its speed?

chrisyaxley said:

The three thermo sensors are attached to the logic board at the end of short cables via the three marked connectors on this image from the service manual. I believe one is HDD temp, one is for the optical drive & there over is the ambient temp.

Click to expand...

If you strongly feel the issue is a bad thermo sensor...and you can find the repalcement part...and you feel you can replace it yourself...then I would say buy all three sensors...and replace all three (one at a time)...and maybe you get lucky on the first one & solve the issue. If not...then you do the 2nd & then the 3rd.

I know this may sound like overkill...but in the absence of a better diagnostic method...it would work (if a bad thermo sensor is the issue). I'm sure special Apple diagnostic software may be able to identify the exact cause of the high fan speed...but us average folks don't have access to that software. This of course assumes it's a hardware issue...and not something else.

chrisyaxley said:

I think the fan itself doesn't have a sensor, and it just uses these three to decide when to increase its speed?

Click to expand...

Like I mentioned above...I had a bad fan one time that caused this on one of my former MacBook Pro's (at least this is what the Apple Genius at the Apple store told me). This "bad fan" still spun up fine...must have been something else wrong with the fan (maybe is was sending some sort of bad signal to speed up the fans).

- Nick

Would something like iStat be able to help? It wouldn't show the failing one directly, but if one is showing considerably hotter than the others, it's a candidate.

https://bjango.com

What app did you install, to control the fan? I use Macs Fan Control, https://www.crystalidea.com/macs-fan-control, which should (hopefully) tell you which sensor, is affecting the fan.

I was going to ask what third-party fan app was used, and if it wasn't, I'd also suggest Macs Fan Control.app as Bob also suggested above.

BTW: Have you checked that the air vents are not plugged???






- Patrick
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Yeah, I am running Macs Fan Control.app, it doesn't seem to effect to the fan at all, and all the temperatures seem perfectly within reason too. I will take a screen shot tonight to help explain.
All the vents are spotlessly clean.

I will install iStat tonight too.

Thanks all