At last it's solved
Thank-you for the update.
Thanks for coming back on this.....
no audio device
Had the same problem on a newly build computer.
Read the forum and solve my problem
I downloaded the drivers from Asus Realtek HD
The form said to go to add, remove problems in control panel.
Removed Realtex High Def
I was suppose to reboot in safe mode but couldn't do it.
So just rebooted and installed Asus Realtek HD drivers.
And after two days of trying to get sound.
Bingo! Great sound.
Try it the only thing left was return the motherboard.
A good tech would of may me look silly.
I hope it help some one else.
And thanks for helping me.