Diagnosis
A blinking white light means it's powered on but isn't receiving an audio signal from your TV. It's in standby, waiting for input.
How to Fix It
This is almost always a TV settings issue. On your TV remote, go into the audio or sound settings. You're looking for 'Audio Output' or 'Speakers'. Change it from 'TV Speakers' to 'External Speakers' or 'Audio System'. If you're using the HDMI ARC port (the best connection), also make sure 'HDMI-CEC' or a similar control feature is turned ON in both the TV and soundbar menus.
If That Didn't Work
Double-check your physical connection. If using HDMI ARC, make sure the cable is in the specific HDMI ARC port on your TV (it's usually labeled). Try a different HDMI cable if you have one. As a test, switch to the optical cable input on the soundbar to see if sound returns.
Heads Up
Some TVs need you to turn the internal speakers OFF and change the audio format to PCM or Bitstream for the soundbar to work right. It's a two-step process.