I just moved out of my dorm yesterday, and when everything was hooked up there, I had no problem. I had my Playstation 2 hooked into the purple A/V input box that came with my ATI TV Wonder, and video and audio worked just fine. However, when I hooked it all up correctly here at home, I'm getting video, but no audio. I've eliminated the console as a culprit, because both my XBox and PS2 have the problem when connected to the TV Wonder. I'm also sure it's not my computer, as it plays all other audio just fine, but any audio coming from the connected console is non-existant, while the video comes through just fine. It's almost as if the purple A/V box had both of its audio-in jacks damaged in the move, but the video jack survived just fine.
TV Wonder has an audio passthrough to the sound card. Have you tried the TV feature? Do you get audio from that?
It's also possible for the LINE IN jack to be muted in the Windows sound bar. Sometimes it's not shown, you can choose to have it shown in properties for the Windows sound bar.
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