Apple 24-inch mid 2007 Personal Computer User Manual


 
iMac (24-inch Mid 2007) Take Apart — Symptom Charts 228
Fans are running at a constant high speed.
If the fans on the system are running at a constant high speed, or ramp very quickly to high
speed and do not vary once this speed is reached, the fans are most likely receiving incorrect
thermal input. Follow these steps:
Reset the SM1. C and then test to see if the fans still exhibit the issue.
Make sure the LCD temp sensor cable is fully inserted into the connector on the bottom left 2.
corner of the logic board.
Boot to the EF1 tests of the latest version of Apple Service Diagnostic, version 3S116 This 3.
will test the fans and thermal input of the sensors. If the tests fail, replace the component(s)
indicated by the test.