New sound system, radio works but the 7.1 on the tv doesn't

[Chae41]

I have installed 7.1 surround sound. My bar, front, and back are fine with the tv, but I can't get the sub or the surround back to work on the tv.

 

[Pavel Horniak]

Same issue. I have SONY Bravia Android TV, and when i connected optical wire to my 5.1 then only front speakers and subwoofer works. now i am using stereo cable and prologic on my audio system.

 

[americanaudiophile]

Check the audio menu in the TV and see if you can change the audio output type.
If not then you could use an HDMI input selector with audio extraction to bypass the TV for external sources.