I don't know how to test with a multimetere or if it's even possible. Go into your bios and make sure onboard audio is enabled. If you built this computer, go to the motherboard manufacturer's web site and download the necessary audio drivers. If this is a purchased system (Dell, gateway, HP,...) go to their web site and download the audio drivers from there.
Also, check the device manager and make sure your audio device shows up properly.