Specifications

iMac (Early 2006 17-inch) Troubleshooting — Symptom Charts 152
article 152349, “Replacing a disk before it fails.”
Shut down the computer, remove the power cord and any other connected cables, and
remove the access door, front bezel, and EMI shield.
Stand up the computer, plug it in, and start it up by pressing the external power button.
As the machine starts up, listen carefully to each of the three fans, and see if you can locate
the fan from which the objectionable ticking, whistling, or squealing sound is coming. The
CPU fan is the left-most fan, the hard drive fan is in the center, and the optical drive fan is on
the right.
Can you pinpoint the fan making the sound?
Yes: Replace the noisy fan.
No: If you can hear an objectionable ticking, whistling, or squealing sound, but you cannot
identify the source of the sound, contact Apple Technical Support.
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 SMC and then test to see if the fans still exhibit the issue.
Boot to Apple Service Diagnostic v3S100 EF1 tests. This will test the fans and thermal input of
the sensors. If the tests fail, replace the component (s) indicated by the test.
Verify that the hard drive temperature sensor cable, and the optical drive temperature
sensor cable are plugged in correctly. If necessary, replace the hard drive and optical drive
temperature sensor cables.
Replace the hard drive and optical drive temperature sensors.
Replace the hard drive.
Replace the logic board.
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