The basic input/output system on an ASUS motherboard controls which on-board devices are enabled after the computer boots. Some ASUS motherboards have an option in the BIOS that allows users to enable or disable integrated audio. If integrated audio is disabled, the computer won't play sound. If the BIOS settings are correct, but the computer still doesn't play sound, the audio cables might not be connected to the speaker jacks on the computer case or disc player.
Press the "Del" key after turning on the computer to go to BIOS set-up. Use the right- and left-arrow keys to select the "Advanced" tab.
Use the up- and down-arrow keys to select the "Onboard Device Configuration" option. Press "Enter" to open the sub-menu.
Scroll to "AC97 Audio" or "High Definition Audio." Use the "+" and "-" keys to change the option to "Enabled." Press "F10" to save and exit the BIOS.
Turn off the computer. Remove the power cable from the computer. Use a Phillips head screwdriver to unscrew the cover panel from the computer case.
Remove the cover panel, then touch the metal part of the chassis to ground yourself. Set the computer on its side so that the bottom of the motherboard is facing the floor.
Locate the 10-pin front panel audio cable attached to the chassis. Connect the opposite end of the cable to the 10-pin audio connector on the back of the Asus motherboard, located perpendicular to the SATA ports and just above the motherboard's product ID.
Attach the black end of a 4-pin internal audio connector to the DVD- or CD-ROM drive, MPEG card or TV tuner card. Insert the white end of the connector into the 4-pin slot located just above the 10-pin front panel audio connector.
Reassemble the computer. Turn on the PC and plug headphones or speakers into the light blue audio jack on the front or back of the computer.
Log in to Windows. Click "Start," then click "Control Panel." Click "Hardware and Sound," then click "Sound."
Select the speaker device from the "Playback" tab. Click "Properties." Click the "Advanced" tab.
Click the "Test" button to test the sound on the motherboard.
The BIOS set-up utility varies from model to model. Check your motherboard's manual on the ASUS web site for further assistance, if necessary.