I would try that just for the heck of it, not a very clear manual but usually there is some kind of a sound manager involved where you can select your speaker configuration like you do in sound properties in control panel.
Install latest drivers and ensure that output hasn't been muted on the full control panel
I'm not sure for this set up but you may not want digital output and may want analogue output, try all the different output options to see if one works
You don't say what speakers but check speakers are powered up and that input is suitable for computer output, no good expecting sound if you have a couple of Hi Fi speakers that expect a Hi Fi amplifier output rather than a computer output which is enough to power earphones but not normal hi fi speakers.
Apologise if this is too Mickey Mouse but as often as not it's something very simple