Dear Big Picture Big Sound,
I have a 40-inch Samsung TV (UN40D5003BF). It doesn't have any audio output (not digital or RCA analog). How can i connect my Logitech Z906 home theater system to the TV?
Thanks for writing in. I've actually never seen a modern TV without a digital audio output (usually a fiberoptic digital output), but I checked the manual for your TV and it looks like you are correct. I don't see either an analog (RCA jacks or mini headphone jack) or a digital audio output on your TV. So really, you can't connect your TV directly to your Logitech surround sound system.
If you are using a cable box or satellite set top box, then you can use the digital audio output from that box and connect it directly to either the fiberoptic or coax digital inputs on the Logitech system and get your TV sound that way. You would still connect the HDMI output from the cable or satellite box directly to the TV to get a picture, but connect the digital or analog audio outputs to the Logitech home theater system to get sound.
For some cable boxes, you have to choose between sending audio over the HDMI cable or the digital audio cable. So if you don't get sound from the Logitech when connecting the cable box to it directly, get into your cable box settings menu and make the necessary adjustment to the audio output.
If you connect the set top box audio directly to the home theater system, be sure your volume is low or off on the TV speakers when you listen through the Logitech system, otherwise you may get an echo or audio delay effect that won't sound so good.
If you are trying to use the TV's built-in ATSC tuner to watch HD programs and still want to use the home theater system for sound, then you'll actually have to the return the TV and get one that does have a digital or analog audio output.
Hope that helps.