I have an LG LCD too and connected my xbox to the same spot when I was waiting for a second HDMI cable and it worked fine. Make sure you are on the proper display, should be S-video 2 if it is on the side, at least if it is similar to mine. Failing that, connect something you know works to that port, direct tv for example. If you get picture, something is wrong with your xbox cables, if you don't I hope your tv is under warranty.
Above all though, move up to hdmi!
Actually, I did unplug the directv from the back and connect it to the side, and I did not get a picture. So you think the problem is with the TV,then? It's about two years old, but I just figured I must be doing something wrong. Never occurred to me the problem would be the TV connection. Thanks for your help. But you're saying, no matter how I connect it, I should get hdmi cables? I'll do that just as soon as I find out what they are. Thank you for your thoughtful answer.