My PC has an ASUS A7N8X-E main board that has an onboard sound card. This has been sufficient because my hearing is bad. All at once I lose my sound capability. I have checked every thing including accidental muting. I installed new drivers. Still no sound. I know that the speaker system is working. Should I assume that the integrated sound processor has failed? Are there any suggestions for further checks that I might make? I am just barely computer literate.