It is unlikely that you have a bad motherboard. In installing and replacing hundreds of motherboards over the years, I've never seen lack of audio as a symptom of a bad motherboard. It is most likely either a driver or a configuration issue. Here are the steps I would take in troubleshooting the lack of audio on your system -
First of all, ensure that you've downloaded and installed the correct audio drivers for your operating system -
GA G41M Combo rev 1 3 Motherboard GIGABYTE
Once you have the proper Audio Drivers installed (and any other drivers you may need for the motherboard from the Gigabyte website), you need to ensure your audio mixer controls are working properly.
Click on the speaker icon in your system tray, then raise the volume level. When you click on the volume level slider itself, you should hear a "ding" sound each time you click on it.
If no sound is heard, click on "Mixer" below the volume level slider.
raise the levels of each item that shows, and unmute anything that is muted. Click on the volume control slider and you should hear a tone.
As far as recording goes, you didn't mention what software program you are using to record with, so I can't help you there. However, if you right click on the speaker icon in the system tray, you can select Recording Devices.
Ensure no recording devices are muted, and raise the levels of any devices that show there.
At this point, you should have sound at least coming through the speakers / headphones. If the microphone volume is too soft, you can enable microphone boost by doing the following -
Click on the start button.
Click on Control Panel
Click on "Harware and Sound"
Under "Sound", click on "manage audio devices"
Select the "Recording" tab, then click on Microphone.
Click on "properties" button in the lower right side of screen.
Click on "Custom" tab, and check "Microphone boost".
Click the OK buttons to accept the changes and close the screen