I'm trying to get my new TCL TV audio into an old Bose 321 media center instead of buying a soundbar. Although Bose may not be great sound I've had it for years with little use. My cable service is new fiber from a Cisco settop box HDMI into the tv, and I interface the Bose with an optical cable audio and a RCA cable video. Media center DVD plays but I cannot get audio from the TCL nor setup video from the media center. The media center displays some options. Suggestions?