iMac - toslink not working

Alright, I just got from work and finally received my mini-toslink to toslink cable and dying to finally connect it from my 20" imac to my 37" samsung HDtv.

however, ive been stuck on google and a bunch of forums because it simply does not work, some sites say to modify my midi devices, my audio devices, my tv, can anybody, please help me out?

The only thing i know for sure is that when i got in system preferences / sound, and look at digital in, it says "the selected device has no input controls"

thank you