Unless you TV has an Audio out, this is not possible.
If you have a set top box, connect that to the Onkyo, and the Onkyo to the TV,. If you have a HD STB, that will have an HDMI. Elase you have to use composite all the way.
I was unable to find any Audio Return Channel (ARC) support in the specs of the tv, so I presume it does not support ARC. If that is the case then your only option is to run an optical cable from TV to 3500:
TV optical out > onkyo HT-S3500 optical in : Optical cable
If your tv does support ARC, then you can use HDMI:
TV > onkyo HT-S3500 : HDMI cable
ensure you enable ARC on the tv and the HT.