Took over a pair of external speakers. Audio came through on 
those, and when I unplugged them audio came from the external 
speakers. From what I read online this is a hardware issue where 
the optical audio is somehow physically selected, without any 
optical audio device attached. Plugging in a standard audio cable 
can reset this

Took a look at the computer. Volume control was grayed out,  
internal speakers were not selectable as an output.

Tried a few potential fixes I found online including resetting the 
PRAM and clearing out the audio preferences in Library/Audio, 
neither had any effect.
Computer also was connected to the network, but network 
accounts could not log in, only hers. 

Ran out of time to finish it this morning, and she says she is 
busy the rest of this week, will call to reschedule on monday. 

left vm

When she tries to play anything with audio, it
won't allow her to change the volume.  When she
goes to system preferences, it says no output
device is selected.  It works sporadically, and
when it stops working, her wireless also stops.  

She says that UCS had been able to fix it before,
and she would like to be shown how to fix it.