iMac Fan is running all the time
OK I purchased a mid 2011, 21.5, i5, 2.5ghz iMac from ebay the other day that was listed as slightly faulty. As I was looking to buy my first iMac and I had a tight budget I thought I'd give it a go. I work with computers and thought I could have a go at fixing the issues.
So this brings me to the problem, the seller said it was bought as part of an office clearance so not much history behind it and that when it was on one of the fans was noisy.
It's arrived today and true to form one of the fans is noisy. I've spent the past couple of hours researching the issue on the internet. First thing I did was run the online AHT. This brought back an error code of 4MOT/4/40000002
I then downloaded smcfancontrol. Currently the ODD fan is running at 4300rpm and 46 degrees (I presume this is the noisy fan I hear). The HDD 1099rpm and 46 degrees and the CPU fan 0rpm and 46 degrees?
So I suppose my question is, where do I start to fix this? Why would a faulty cpu fan make the odd fan run at max?
Thanks in advance
To keep you from cooking the CPU. When some of the sensors or fans fail by default mode all the fans kick into high to try to keep the user from killing the CPU by continued use of a faulty machine. Try replacing the fan AHT identified (you are correct the EFI blames the CPU fan).
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