User Guide

Troubleshooting General/ Sound Out Flow - 14
Sound Out Flow
The iMac has three sound out paths: to the built-in speakers, to
the sound output jack, and to the headphone jacks.
To transmit sound out the internal speakers, the sound signals
must travel (via the short internal audio cable) from the J14
audio connector on the logic board to the J1 connector on the A/V
interconnect board. From there, the signals are transmitted to the
J6 connector on the other side of the A/V interconnect board. And
then the sound out signals travel via the long internal audio cable
to the internal speakers.
Sound that is transmitted to the external speakers travels directly
from the sound out connector on the logic board to the external
speakers via their external cable hookup.
Click here
to see an animation of how the sound-out signals travel
through the iMac.
Processor Module
The iMac logic board comes with a removable processor module,
which can be replaced. The processor should rarely fail and should
be replaced only as a last resort. Processor modules can be
ordered from Service.
Logic Board Battery
The battery on the logic board controls the stored system settings,
such as date and time. It is important to note that the battery does
not affect power at startup.
The battery should be replaced if the system loses date and time
settings.
Note:
The iMac uses a lithium battery that must be disposed of in
accordance with hazardous waste regulations.