Hi there! If the video on the TV and audio from the HW-A550 Soundbar are not synchronized, select SYNC in SOUND CONTROL (looks like a gear), and then set the audio delay between 0~300 milliseconds by using the Up/Down buttons.
If you should need further assistance, please contact Samsung Customer Support at: 1-800-SAMSUNG (ask for Soundbars), available 8AM -12AM EST, 7 days a week, text HELP to 62913, LiveChat on Samsung.com, or Email: https://www.samsung.com/us/support/#contact_us_for_support ^Gina