Did not work - Thanks
Vizio model # XXXXX VO37OM
The RCA cable is plugged into audio (red/white) in the back of the TV (not the audio out red/white)
There is no 3.5mm written but there is a headphone jack that says "audio" (my headphone jack fit perfectly), in the same "blue" panel where I plugged in the VGA cable. An "a-ha" moment?
Yes, a-ha exactly. I was expecting this was the issue.
Most tvs that have a vga input have a matching minijack input for pc audio. The rca ports you are using are for another input mode (component/composite connections for a dvd player, cable box, etc)
What you need to do is run a 3.5mm minijack to minijack cable (headphone type plug on both ends) from the computer to that port on the tv, and you should get normal sound.