You need optical cable for this.I don't think ARC was a thing 10 years ago. Then set up your TV to use external speakers (settings-sound-speakers). Set to external. And under the same sound settings there's an option for digital out..... Since I havo no idea what that HT can receive and decode through optical input I wont tell you use "this" but try. In worst case scenario you should be able to get 2 channel audio and then use some of those sound modes to recreate some surround.
well, if you do have a sound from your TV coming out in stereo then try with different setting on the TV but keep in mind the limitation of optical out and all those passthrough problems. Your best bet is to test that with built in video player and some movie with known audio format (DD or DTS) on USB. And then play with those sound modes on your DAV. Basically it should work the same way as it does when watching DVDs. So if you are watching something with DD or DTS and your passthrough is setup correctly, using AFD (auto format decode) on DAV should give you surround sound. In case of stereo input from regular TV broadcast or some old movie you should use some of those virtual surround modes.
