Install updated drivers and then check your motherboard connection for audio. Does the sound come back when you reinstall the GT 850?
I've already update my driver but still no sound......anyway when i replaced the graphic card. i saw a cable which need to unplug & i believe it was a connection for the audio.But this new graphic card was build in sound card.So i'm a bit confused about it.What shall i do next? FYI, my old graphic card was damage before,so i better not to used it anymore
Check to make sure you have some type of audio software installed; Windows should automatically have something like that. After that, go into Control Panel > Sound > Manage audio devices. It may be different for you if you have a different OS than windows 7.