If the video doesn't contain a digital audio signal, you won't hear sound through this connection. This feature is available on certain digital broadcasts and streaming video, and isn't supported on standard cable or analog stations. The optical jack is designed to output sound when the video you're watching contains digital audio (PCM or Dolby Digital® technology).
The following situations may cause this issue: Check Applicable Products and Categories for details. IMPORTANT: This article applies only to specific products and/or operating systems.