Mac Mini 3,1 fan does not work with SSD installed

[schmani]

Dear all,

I encountered a very odd problem recently while trying to upgrade my mothers Mac Mini (3,1 2009). I wanted to install a SSD drive and first purchased a Crucial M4 128 GB. Following the excellent manual provided on ifixit.com it took me just 15min to do so. Mac OS installed perfectly but the Mini would always shut down while installing Windows 7 via Boot Camp. Thinking this was an issue with the Crucial SSD, I exchanged it for a Samsung 840. The installation of Windows 7 worked, but once I wanted to install drivers, the Mini shut down again.
I discovered that when the SSD is in the Mini, the fan won't work and the sensor correctly reads 0 rpm. Boot Camp / Windows 7 seems to have a higher cpu load than OS X so that it shuts down quicker. When I did a quick stress test in Mac OS, the mini would shut down after a few minutes too. (Apple Hardware Test (AHT) also tells me that the Fan Motor does not work)
Now comes the strange part. First I assumed I broke a cable or the temp sensor (although I used extreme caution and would describe myself as experienced with these kind of tasks).
However, when I reinstall the old 160GB HDD, the Fan will work perfectly, without any errors in AHT.

Does anyone have a clue why the fan spins normally with the original HDD installed and won't even start with 2 different SSDs? I want my mom to profit from the superior SSD speed, but when the fan simply won't work, this is not an option.

Kind regards from Germany,
Daniel

 

[chrfr]

I discovered that when the SSD is in the Mini, the fan won't work and the sensor correctly reads 0 rpm.

Is it possible you accidentally caught something in the fan when you reassembled the computer, preventing the fan from spinning?

 

[bplein]

I am writing this from a Mac mini 3,1 with a Samsung 830 SSD. Fan works fine.

I noted that the hard drive also grounded to the chassis using a metallic fabric-like thing. My SSD didn't have metal exposed there, so I scratched some paint off the surface where the connection is made.

It's a long shot, but maybe that's a requirement?

----

edited later

The above may have been on my Mac mini 1,1, which I also upgraded with an SSD, and that is off site. I don't plan on opening up my 3,1 any time soon to verify.

 

[schmani]

@ chrfr: I have carefully reassembled it and checked the fan. At least nothing visible can be caught in the fan. The steps I did while reassembling with SSD and HDD were identical.

@ bplein: The HDD had two little grey "place holders" out of facbric on the bottom. I reattached them at the exact position on the SSD. However, the space under the SSD is plastic (presumably to separate the SSD from the SuperDrive). Can you maybe identify what you meant from this manual: http://www.ifixit.com/Guide/Mac+mini+Model+A1283+Hard+Drive+Replacement/1063/1 ?

Thanks for the responses so far!

 

[bplein]

@ bplein: The HDD had two little grey "place holders" out of facbric on the bottom. I reattached them at the exact position on the SSD. However, the space under the SSD is plastic (presumably to separate the SSD from the SuperDrive).

They aren't in that picture at iFixit, but they are as you describe, a metallic fabric. I assumed that they were used to ground the hard drive to the optical drive, since the hard drive is isolated in a plastic frame.

My SSD had a metal cover on it, with a finish/paint. I scraped away the finish to expose metal, as I assumed that the grounding was important.

I cannot tell you that this grounding is what is causing your issue, however!

 

[Ngorkes]

I just installed a 840 pro in my mac mini 2012 and i am having the same issue.