Howdy,
Im assuming that you are refering to the A/V cable that goes from the back of the system and to the tv via A/V
I did a quick search on ebay and here is one:
<a href="http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3022726196&category=4792" target="_blank">http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3022726196&category=4792</a>