Upgraded motherboard and audio chips - no sound in RH7.3

I've just upgraded my motherboard - a Gygabyte 7VKML with an on-board AC97 VIA 
sound chipset - but I can't get any sound out of the system at all.

The modules.conf file reads:

alias parport_lowlevel parport_pc
alias eth0 8139too
alias sound-slot-0 via82cxxx_audio
post-install sound-slot-0 /bin/aumix-minimal -f /etc/.aumixrc -L >/dev/null 
2>&1 || :
pre-remove sound-slot-0 /bin/aumix-minimal -f /etc/.aumixrc -S >/dev/null 2>&1 
|| :
alias usb-controller usb-uhci

I think this is correct, and I don't get any error messages, but still not a 
peep 

I've also downloaded driver files from viaarena.com, but I'm really not sure 
what to do with them or how to install them (still very much the newbie).

Can someone help me with some easy to follow "sound" advice, please?

In anticipation,

Lloyd