[CentOS] No sound on HP 8540w, guidance requested

Sat May 7 15:22:58 UTC 2011
David <David at daku.org>

Dear Experts

I have been unsuccessful getting the sound to work on a HP Mobile 
Workstation HP 8540w.

Here's a brief rundown of where I am

I did a clean new install of Centos 5.6 from DVD, using the Gnome 
Desktop option and no optional modules.
I enabled the firewall, but disabled SELINUX.

I installed three files from elrepo to make the wireless adaptor 
work, and specified the video adaptor using the Gnome -> System -> 
Preferences -> Display panel.

I ran "yum update" until all updates were completed, rebooted system 
because the Kernel changed.

The system now works -- all of the following appear to function properly:
  - USB connections
  - wireless
  - ethernet
  - pointer-stick for the mouse
  - the display at its "natural" resolution (1920x1200)
  - An occassional beep does occur, proving that the PC speaker is connected.

However, I when I play any sound or movie file, I get no sound.  I 
know that the PC speaker produces low quality sound, but there should 
be something.

I have experimented with the "Sound" setup, but none of the options 
seem to produce good results.

Is there some special driver or option I need?

Any assistance or direction would be appreciated.