Without the model number of the TV we can't check on what audio outputs it has. The most likely is toslink optical audio. Your Bose has this input so you should just need an optical cable. The Bose has all three possible inputs you might need (coax digital and analog RCA). Use the digital connections for better quality.
How to connect Old Bose 48 lifestyle system to a Samsung TV with HDMI links
Hi, William. I don't think the answer given so far actually addresses your dilemma. I also have an older Bose Lifestyle receiver and a new Samsung TV. The problem is not getting the signal from the TV to the Bose receiver, it's the other direction. We need to get the RCA output from our Bose receiver out to the TV which has only HDMI inputs. We need that connection to play DVDs or to even calibrate the system with the Adapt IQ DVD.
I believe we need a composite (RCA) video output to HDMI input converter.
Any help out there would be greatly appreciated.