Hi flukezoid,
What is the make and model of the motherboard? The problem might be nothing more serious than incorrect wiring to the audio front panel header. Here is the relevant page from my motherboard manual. Although it is probably not the same motherboard as your friend's (see my specs), the header layout and pin configuration is standard. Check the connections according to this diagram. The upper pin layout is for an AC'97 front panel, whereas the bottom pin layout is for a HD front panel.
