Q: Mac Mini late 2009 no sound through thunderbolt

Hi folks I am fairly a newbie with mac os and hardware, I have a mac mini 2009 server edition which had server os installed I blew it away and installed snow leopard, did the updates lol apple does it different eh? Anywho did the upgrade took a look at settings sound and its blank nada nothing in there, the midi app in the app folder saw nothing as well, when I look at mac config IT sees the tv so why isn't there any sound? I do not have a problem with windows or linux playing sound through my tv strange, tried the mini hdmi to hdmi and the same getup nothing. Or the person I bought this off reckons he had no problem getting sound through his monitor, I beginning to be a bit doubtful about this. But what can I say, thanks in advance for any help, I really do not want to take this to a repair shop. This should be a simple fix somewhere lol