My tv is connected to my blu-ray surround sound with the optical cable. It worked fine and then my power went out and there is no sound through surround sound. I don't know how to set it up through settings on tv?
Make sure both ends of the optical cable are seated right, there are many bad optical cables included with devices nowadays. An optical cable can go bad its glass it can be cracked if bent too far. When an optical cable is all black it very hard to see the orientation of the tip, and since the optical cable only goes in one way. Having a cable with contrasting color along with black helps a great deal in sitting the cable right. It works like batter's eye.
