Fan stuck at full speed

fan spins to 100% immediately on boot. and stays at 100% i just cleanly wiped the mini same results.

just did the in depth diag test and got the following result:

4m0t/1/40000003: Exhaust - 6653

my main concern is i voided the warranty, im not sure where to go with this now. i work on machines all day long (im a win server admin, and have been for years)

i would consider replacing the exhaust fan part: 610-0164 but i cannot find it anywhere.

I found that every time I want to my Mac mini 2.5Ghz 16GB that it was hot and the fan was on full. Just followed Franks advice and found that the Google Drive app was at 96% of my CPU capacity. I killed the app and the fan slowed down with about a minute and within 2 mins all was quiet. Thanks for the tip Frank

My Plex server was doing n library update and the service got stuck.

I had this problem after change my hdd and the problem was the connector for me too.

Same issue after replacing the HDD with an SSD. The issue for me was a tiny little wire that went into one of the sensors had come out just a bit, enough to break the connection. After using needle nose to slip it back up into the clip the fan worked fine. Also note that the CD and HDD sensors are the same size and approximate length. It seems possible to swap the two accidentally. Good luck.

@aac197, can you post a picture of your jumper wire and the pads that were jumped? I'm having the exact same problem but I don't have an oscilloscope. Thank you!

Thank you AAC197 for the tip about the little smd component just next to the fan connector, somehow it got unsoldered and there was no contact, there are 3 components, and the one close to the fan connector was the issue. I checked with my multimeter and there was no connection, it seems to be a little diode or something because checking continuity after fix there was no resistance, one of the fan pins goes through it. Thank you again, also I had this SSD fan control application that did not work until I got this fixed.

== Update ==

My board had 3 connector for the sensor's, 1 was for the hd temperature, DVD temperature, and 1 for ambient temperature. If you don't see 1 it is probably broken take a good picture of where the fan connector is at surrounding area, and I could point you where is it supposed to be.

same issue here, but i can't find the component. How can i solve this? Just bridge the connection?

thanks for your help

Hi Step I checked, with my multitester and it seems it is not a diode, measured resistance on it and I got 0.4 ohm resistance, my multimeter shows 0.2 ohm resistance if nothing is on the way. It can be a smd cap but not sure, I wish I could help more.

Hi, When I had this problem, I gave it to a friend of mine with a full electronics workshop in his garage. Using an oscilloscope, he was able to see the fan control signal on one of the solder pads of the missing component. He was then also able to see that the other solder pad was connected to the fan control pin of the fan connector.

He then measured the impedance of the fan control circuit of the fan and the motherboard and was able to deduce (based on similar low voltage fan controller designs) that the missing component was either a low or no voltage jumper component.

As such he then just bridged the two pads with small piece of wire and my mac mini has been working flawlessly for 2 years now!

As Lui has measured this to be 0.2 ohms, I suspect that what has been done to mine is absolutely fine. My friend doesn't believe that this component would have been a capacitor.

Hope this helps!

It would have been even more helpful if I didn't already find the answer on my Mac! ;) I just bought a MacMini mid-2010 second hand. It has an SSD in it, and even though the body was completely cool, the fan was running at maximum speed, which is quite distracting. tiny file, that doesn't really need Automator, I found on the computer.

It was a plain text file called "slowfan". All I had to do was drag and drop it into Terminal, (after I read it -- don't run code you don't know what it will do). So if anyone else wants this they can just copy and paste it into a plain text file and put it in ~/Apps or a similarly helpful place. (You need to create the "Apps" folder first, in your User Home folder.)

#! /bin/bash

/Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 2ee0

Sadly, the software solution is not a good long term fix. Over time you will wear out the fan bearings and/or shorten the systems lifespan. There are people with micro soldering skills that might be able to fix the damage. I would recommend you give them a try.

Is this your opinion or experienced fact?

The web site that led me to this software also offered that apple had a fan control app, that did the same thing , but it was developed for the iMac which employs more than 1 fan and therefore wasn't ideal for the mini. The forum is on Macgurus.com. The software I suggested has been used since at least 2013 on both macs and pcs with no negative feedback I could find. If you know otherwise I am interested. For the time being I am watching the included temperature samplings and fan speed analog while I decide on soldering equipment to tackle the job myself. I have some experience soldering communication cables for our earlier years of networking CNC machines with our engineering and programming departments.

I am also aware that some companies build fixes into their systems but don't necessarily advertise them so that they don't have to employ highly trained technicians to repair their products.

Thanks

Sadly, from experience working on Mac systems over 20 years this band-aid solution is not ideal. Between burnt out fans & systems it is a costly venture over the long haul. -

Apple fan control is via hardware (SMC services) which works via the core OS (and not controllable by the user). Apple does not offer any fan control application to access it. Apple uses thermal sensors and tachometers built into the fans to monitor both the temp of different things running in your system and how fast the fans need to run to remove the heat buildup dynamically. I would recommend you use a good monitoring app that allows you to see visually what the sensors and fans are doing. I like this one: Temperature Gauge Pro. While it also allows you to set the fans I discourage its use for that. Instead see what sensor and/or fan are doing so you can then address the correct repairs the system needs.

thank you. I re read the forum I mentioned above and found that I had misread the part about apple. I will try the program that you suggested in order to compare it to the info my program is giving me, however I am still looking at soldering stations. I guess I am so used to 5 year obsolescence using PC's that having a system that is still useful at this time makes me brave about digging into it.

Before you warm up the soldering station, first figure out what you need to fix. Often the issue is just a loose wire (connector) or a damaged part.

You should plan for a yearly clean up dusting out your system. You also may want to look at where your system is. Do you have a shedding dog or rug? Do you tend to run the vacuum around a lot? You maybe need to address the area as well.

I also don't recommend using fan over-ride software as time has proved they end up doing more harm than good!