Early and Late 2006 iMac High Fan Speed
If your fan is always running fast and loud, and you had the Hard drive replaced, it is highly likely that the Thermal Sensor fell of, or was not replaced on the new Hard drive.
My three year extended warranty was near expiration when the drive went, and the repair took place at the Apple store. When I took it back because of the loud fan it was just past the three year mark and they wanted to charge me to diagnose the problem. So I decided to see if I could resolve the issue on my own.
The symptoms are similar to an SMC issue, and the instructions to reset the SMC are easy to find in the Apple Support section. However, resetting the SMC did not work for me. After a lot of research I found a link to an online Take Apart manual and started the ardous process of disassembling the system (related link: http://www.scribd.com/doc/25006796/Apple-Intel-iMac-Hardware-Service-Manual).
It was readily apparent that the mini circuit board with the sensor was not transfered from the old to the new Hard drive, and had to order a replacement online. The part number is 922-7242, and typing that number plus the word "iMac" into a search engine will show you several sources for a replacement part.
Hope this post saves somebody time in fixing their similar issue.
My three year extended warranty was near expiration when the drive went, and the repair took place at the Apple store. When I took it back because of the loud fan it was just past the three year mark and they wanted to charge me to diagnose the problem. So I decided to see if I could resolve the issue on my own.
The symptoms are similar to an SMC issue, and the instructions to reset the SMC are easy to find in the Apple Support section. However, resetting the SMC did not work for me. After a lot of research I found a link to an online Take Apart manual and started the ardous process of disassembling the system (related link: http://www.scribd.com/doc/25006796/Apple-Intel-iMac-Hardware-Service-Manual).
It was readily apparent that the mini circuit board with the sensor was not transfered from the old to the new Hard drive, and had to order a replacement online. The part number is 922-7242, and typing that number plus the word "iMac" into a search engine will show you several sources for a replacement part.
Hope this post saves somebody time in fixing their similar issue.
Too Many to list, Mac OS X (10.6.2)