Ursprünglicher Beitrag von: Brandon Genius ,
I had the local Reseller and service centre put in a new 2 TB drive. When I got it back after about 2 min the fan for the hard drive went to 5500RPM. After talking to someone that worked directly with apple, they told me to check the sensor cable to the drive and make sure the white dot is facing up. Remember to have that plug, plugged in closest to the sata connector. Everything is working fine now.