you need to specify what you mean. you say you have "via hd audio" but do not say what does and does not work audio wise.
do neither the front nor rear jacks work for audio? if that is what you meant...
-completely uninstall any audio drivers. go to the manufacturer of your motherboard's website and download the newest ones. restart. does it work now (check front and rear)
its probably just a driver issue, although i suppose you could have a hardware issue with your sound. if you are getting no sound as-is then you would get none on the keyboard as it connects via the same jacks for audio.
if your onboard audio is in fact dead you could use a soundcard or usb soundcard (or use usb headsets) to get audio. check that its not driver...