Macbook-Sharp Aquos Sound Issue

[spikespike]

I've connected my early 2008 Macbook to a brand new Sharp Aquos 32 inch flatscreen HD 1080p TV via a mini dvi-dvi converter connected to a dvi converter-HDMI that is plugged into the TV. The image shows up fine (macrumors is huuge, woo-OOoh!) but when I use an A/V cord plugged into the head phone jack no sound comes out, either from the computer or from the TV. Anyone have any ideas why this might be?

 

[rdowns]

System Preferences>Sound>Output