Diagnosis
That solid white light means the bar is powered on and receiving a signal, but the audio isn't making it to the speakers. This is almost always a wrong input setting on the bar itself.
How to Fix It
Grab the remote. Press the SOURCE button. Watch the light on the soundbar's side. It should cycle through different colors: blue for Bluetooth, white for optical, and red for HDMI ARC. Let it land on the one that matches your actual connection (HDMI ARC if you're using your TV's HDMI ARC port). If you're not sure, just try each one. Wait a few seconds after each press to see if sound kicks in.
If That Didn't Work
Double-check your TV's sound output settings. You need to tell the TV to send audio out to the soundbar, not its own speakers. On most TVs, that's in a menu called something like Sound > Audio Output or Speakers. Set it to “External Speakers” or “HDMI ARC.”
Heads Up
If you're using the optical cable, make sure the little plastic cap on the tip is snapped off before you plug it in. A lot of people miss that.