That is not good.
Are you sure you went into the BIOS and set it to its defaults, saved the settings and exited?
A hard reset, BIOS set to defaults and a complete system recovery -- one or a combination of those three items should restore complete functionality of the audio.
If you are sure you have done all three things and you still have no sound, then I suspect the BIOS update somehow has really messed things up.
I do not think the problem is with the individual speakers, unless they weren't working before the BIOS update ran.
