Getting no sound from sound bar AX510 with Studio XPS 8100 (Is this a Windows 10 issue or is it the sound bar?)

I have good sound with other speakers on this desktop, but I wanted to save some workspace on my desk, so I recently got a new AX510 sound bar and attached it onto a Dell 2208WFP monitor, one of the monitors listed for that soundbar.  It powers up via the AC port built in to the monitor, just like it should, and I've correctly connected the audio cable on the soundbar audio output on my desktop.  But there's no sound at all.  I did get a static "pop" once... but no other sound.

So I am trying to figure out whether the sound bar is defective, or if this is possibly a Windows 10 issue, as I've read a few odd posts on the internet about people suddenly finding that previously working sound bars don't work in Windows 10.... or some other incompatibility (my desktop is a Studio XPS 8100, Windows 10).  I realize all of my equipment is not the latest, but it's all been in great working condition and the one new addition is the sound bar... I did plug my old speakers back in again, and they still work just fine.

I was thinking I can test the sound bar by connecting it to another computer at work (tomorrow) that's running Windows 7.  to determine if it's a Windows 10 issue -- or if it just doesn't work at all -- but would that be a definitive test it's not a Dell computer?  Any other ways to diagnose the problem and pin it down?  I can conceivably still return the sound bar if I determine it's defective...

Thanks!