I've got the same problem. 2002 V32. Everything looks ok but no sound ?? CD no sound either.
It is the amplifier in the back near side panel. The terminals get corroded, and that is the end of that. £400 for a new one, so I am trying to fix mine.
Let me know if you find a low cost refurb place.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix in-car audio.