Hi,
I was trying to upgrade an old iMac mid 2010, 21.5" to El Capitan from 10.6.8, when I noticed that the back of the imac was getting quite hot. I opened the front panel and cleaned the fans etc without removing the logic board etc. The only thing I removed was the HDD. After restarting and working for a few hours I still think that the back is still quite warm, though not at the center (where the HDD is) but on the left and right top corners. I installed the trial version of iStat Menu and though the HDD temp is shown as 49C the HDD proximity is showing 254C.
I did recheck the hard disk sensor cable properly while putting back the HDD. So What exactly is the 'HDD Proximity Sensor' and why would it show this ridiculously high temp when all other temps are below 60C.
Also has anyone ever installed El Capitan on old iMacs? Would it heat up the system more than 10.6?
Regards
Alok