Mac Mini, fan started running full speed tonight?

[PaulexPC]

I have a one year old Mac Mini.
Just this evening when I turned it on the fan is running at full speed, and quite loud. I turned it off an rebooted, still full speed fan.

Oh crap. I think my warranty expired about a month ago.
What could be wrong with it?

Also the front LED is off. I have not opened this unit up since a year ago when my friend and I installed new RAM (the machine was brand new at the time)

 

[Genl. Ludd]

Check for runaway processor

Hi: I had that problem, and found that a processor was taking up 94% of CPU processing.

I found out through the iSTAT widget on the dashboard. It showed a processor with the name starting with AV.

You can go to the Utility > Activity Monitor

Click on the %CPU and see if one is taking up a high percentage.

You can select that process and click Quit Process. When i did it things went back to normal and the fan quieted. It lasted through a restart.

If the user is "root" you might have to be very cautious. You can try it, but it may bomb the system and you will have to restart, but at least you will know it probably isn't your hardware.

 

[billib]

ptmd

I have a one year old Mac Mini.
Just this evening when I turned it on the fan is running at full speed, and quite loud. I turned it off an rebooted, still full speed fan.

Oh crap. I think my warranty expired about a month ago.
What could be wrong with it?

Also the front LED is off. I have not opened this unit up since a year ago when my friend and I installed new RAM (the machine was brand new at the time)

Hi, I don't know about the LED not working but for your processor
problem, launch your "Activity Monitor" located in your Utilities folder.
In its Menu Bar choose "All Processes" in the Drop Down Menu.
Then scroll down to expose "ptmd". Quit it!!!!!!! That should stop
your processor from being hammered and your temperature should
drop back down to something reasonable. Its a known bug. One of
Apples updates should eventually fix it. BTW, I have this problem
on a First Gen. Intel mini.

 

[tchyfeeley]

Mac Mini full speed fan even when off

My Mac mini started the same thing....although, my fan runs at full speed even when it's off. Just plug in the AC power cord and it sounds like a jet engine. This makes me believe that the problem is hardware related....anyone have any ideas?

 

[billib]

Temp. Sensor

My Mac mini started the same thing....although, my fan runs at full speed even when it's off. Just plug in the AC power cord and it sounds like a jet engine. This makes me believe that the problem is hardware related....anyone have any ideas?

People who have detached their temperature sensor from their processor
and not reattach it cause the fan to run full speed with the mini plugged in
and powered up. Sorry. I can't help you with your problem. It sounds like
your Mother Board maybe going bad.

 

[Sun Baked]

Get the system restore disc #1 and restart holding down the D key, and run the Apple Hardware Test.

http://support.apple.com/kb/ht1509

Likely it'll show a 4sns error, which is probably a sensor error.

 

[jlg89]

My Mac mini started the same thing....although, my fan runs at full speed even when it's off. Just plug in the AC power cord and it sounds like a jet engine. This makes me believe that the problem is hardware related....anyone have any ideas?

I also have a late 2009 mini with a fan that comes on full blast as soon as the power cable is plugged in. Apple's diagnostics will tell you it's a bad fan, but given that it's happening before you even hit the power button, that's probably not the issue (I tested mine with a known-good fan, and it did the same thing). My best guess is that the chip that regulates the voltage going to fan is fried, so instead of a variable voltage the fan is getting a full-on 18VDC.

You can measure this by opening the mini, and putting a voltmeter across the black and grey wires on the fan connector--as you're looking at the rear of the mini, with the cover off, the fan connector is near the middle of the small circuit board that hangs at the rear of the optical drive. It's the 3-wire connector with black, blue, and grey wires.

Fan control software won't fix this, because (if I'm right) the chip that the software needs to control is fried. The only "right" way to fix this is with a new logic board. That's not acceptable to me, so I went online and bought a 10 Watt, 220 Ohm resistor, cut the black wire, and put the resistor inline. That drops the fan speed to ~2600 RPM, which is slow enough to be reasonably quiet but fast enough to keep the mini cool under most circumstances.

https://www.alliedelec.com/search/pr...x?SKU=70023234