iMac (27-inch, Mid 2010) Symptom Charts — Input/Output Devices 99
2010-09-09
Deep Dive
Check Result Action Code
1. Verify if boot chime is present
when system is powered
ON. Make sure audio output
preferences are not set to mute
and volume is set to mid-range.
Yes Go to step 2.
No Reset PRAM and retest.
2. Make sure no cables are
connected to external sound
input/output ports. Go to
System Preferences > Sound >
Output and verify that “Internal
speakers” is an available option.
Yes Go to step 3.
No If “Headphones” is the only
available sound output
device, replace audio cable.
If “Digital output” is the
only available sound output
device, reseat audio cable to
logic board. If issue persists,
replace audio cable.
If issue persists, replace logic
board.
L11
L11
M09
3. Go to System Preferences >
Sound > Output. Set speaker
balance 100% to LEFT speaker
and play a known-good sound
le. Verify if sound is generated
by LEFT speaker and that sound
quality is acceptable.
Yes LEFT speaker and amplier
circuitry OK. Go to step 4.
No No audio in LEFT speaker.
Go to step 7.
4. Set speaker balance 100%
to RIGHT speaker and play a
known-good sound le. Verify
if sound is generated by RIGHT
speaker and that sound quality
is acceptable.
Yes RIGHT speaker and amplier
circuitry OK. Set Balance slider
to middle. Go to step 5.
No No audio in RIGHT speaker.
Go to step 7.
5. Verify if user-reported audio
issue has been resolved.
Yes Issue no longer present.
Return system to user.
No Go to step 6.
6. Boot system from Install
DVD or another known-good
bootable volume. Verify if issue
still occurs.
Yes Go to step 7.
No Known-good boot volume
works OK. Troubleshoot for
software issue. Isolate if issue
is application-specic or a
possible OS conict.