I have this old pioneer receiver XV-DV333 surround system. And a new 65inch 4k Toshiba tv. And I thought just connecting the tv to the surround sound via optical cable would work. But it doesn't and I have ran out of options. I will attach photos of the Surround sound box and remote! Any help is appreciated cheers.
If the TV has an optical audio output and the HTS an optical input then you should be able to get it working.
Check the TV audio menu to make sure that the optical audio output is turned on. You may also have to turn the TV speakers off.
Make sure you've selected the optical input on the HTS. I think it's audio line 2.