Have you tried plugging the red and white cables into the other audio inputs?
I recently bought a VGA cable to connect my laptop to my TV. Obviously I know VGA carries no sound, so I also bought a cable that's a 3.5mm headphone jack to red/white audio cables. The problem is that I don't know where to plug the audio cables into. I have to set my TV to PC mode to view use the VGA, and the only audio input right next to the VGA input on my TV (which I should've checked before) is for a headphone jack. Is there any place anybody can think of where I can plug the red/white cables into that the PC input would use, or do I have to buy a 3.5mm to 3.5mm cable?