Aux give stereo only...Check connecting optical cable to TV optical out ...If it works then no issues in cable...Thank you , I selected optical output only in the soundbar. There are two settings in the sound section
1)To enable or disable fixed audio channel output (i enabled and disabled but there is no sound output)
2)Surround sound format (I varied it between the three available options auto ,Dolby and none but there is no sound output)
However I am getting sound output by connecting soundbar to STB through aux cable.