iMac (27-inch, Mid 2010) Symptom Charts — Mechanical 119
2010-09-09
Deep Dive
Check Result Action Code
1. Verify if any tape, gasket, cable
label, or cable is touching
the fan blades and causing a
ticking noise.
Yes Secure the material so it
doesn’t touch fan blades. If
tape adhesive has lost its
stickiness, replace that section
of tape.
No Go to step 2.
2. Run latest available Apple
service utilities and verify if it
reports one or more errors.
Yes Locate aected part and
check for correct cable
seating. Use ASD Error
Codes table and sensors
location table (in General
Troubleshooting) to decode
error. Follow instructions in
table for resolving error, then
retest.
No Go to step 3.
3. Verify if noise sounds like one
or more fans are spinning faster
than expected.
Yes Reset SMC by disconnecting
power cord for ~15 seconds
then retest. If issue continues
go to step 3.
No Go to step 6.
4. Verify if noise changes when
optical drive is being accessed
or media is inserted or ejected.
Yes Suspect issue with optical
drive or media used.
Go to Optical Drive Noisy
symptom ow.
No Go to step 5.
5. Mute the system volume. Verify
if issue still occurs.
Yes Go to step 6.
No Suspect issue with speakers
or audio amplier circuitry.
Go to Audio: Built-in
Speakers Have Distorted
Sound symptom ow.
6. Adjust brightness on display
between maximum and
minimum settings. Verify if
issue changes depending on
brightness level.
Yes Suspect issue with LCD
display or backlight controller
board. Go to Noise/Unstable
Flickering symptom ow.
No Go to step 7.