Chosen Solution
I’ve upgraded my i5 1TB hard drive to a 2TB. There was a 1TB WD Caviar Black and I’ve upgraded to a 2TB Caviar Green. The temperature sensor is working because iStat gives me a temperature around 100F. However the HD Fan starts around 2000rpm and is getting faster and faster (10 min later its at 3700RPM). I took care to use the same manufacturer, but maybe that’s not enough? Or did I miss something when I put it back together? I also did a SMC reset just in case. Anyone have thoughts on this? Have you experienced this? Should I try a different drive?
Thanks for the update mentioning the orientation of the cable - I had made the exact same mistake and was just about to put the original disk back in! So I can also confirm that the WD 2TB Caviar Green works.
