Power Macintosh: System Update 3.0 and Sound In

For users of system software versions 7.1, 7.1.1 (System 7 Pro), or 7.1.2, this article explains how to update your system software so that it retains your sound input source selection.
Symptom
On Power Macintosh computers, the setting for the sound input source resets to 'Microphone' after the computer is restarted or shut down. This is a particular concern when playing audio CDs, since the 'Internal CD' and 'Playthrough' settings have to be reselected each time the computer is restarted or shut down.

Products affected
Macintosh computers with system software versions 7.1, 7.1.1 (System 7 Pro), or 7.1.2 (for Power Macintosh).

Solution
System Update 3.0 partially addresses this issue. The updated Sound control panel retains the 'Microphone' or 'Internal CD' settings, but still does not retain the 'AV Connector' settings. If 'AV Connector' is selected as the 'Sound In' option, the setting reverts to 'Microphone' after the computer is restarted or shut down.

If the 'Internal CD' sound setting is not retained after the installation of System Update 3.0, then the Sound Preferences file is probably unusable. This file can be found in the Preferences folder in the System Folder. Drag this file to the Trash and reset the Sound In settings again.
Published Date: Feb 19, 2012