how do i get sound from my tv while im connecting a 3.5 mm rca cable to it from my computer?

[SIN100]

Cant get sound from tv when i connect the 3.5mm rca cable from the computer to the tv.

 

[americanaudiophile]

How is the PC connected to your TV?
If you are using HDMI set that to carry your audio as well as video. Unless your TV has an HDMI/DVI input there would not be an audio input that is associated with the HDMI input you would select.