So I just got a shiny new HD t.v. to go with my Xbox 360 but I'm already having problems. The thing is when i have all 5 of the cables plugged in and the t.v. on the HD input (i think its called CV1) it works just fine, but when i switch the Xbox cable to HD mode the screen just gets static and the picture disappears. Any help?
Make sure everything's switched off.
Make sure you're not plugging anything else into AV1 on your television set. You should only have the green, red, and blue component cables plugged in to their respective ports and the red and white if you're using your TV for audio. Make sure the yellow cable stays unplugged.
Also, make sure you're not confusing green for blue. They look pretty much the same in the dark behind a TV set.
Turn the switch on the Xbox end of teh connector to HDTV and plug it into your Xbox, making sure it's well seated.
Turn on your television and switch inputs to AV1.
Turn on your Xbox. Wait.
Your television should autodetect the signal and adjust itself. Once you get a picture, make sure to select the best HDTV settings for your television from the setup menu on the Xbox (in your case, I recommend 720p, intermediate).
If you're still having problems, you could have a bad cable, bad Xbox, or bad television. Most likely, it's just a bad cable. If you have anything else that outputs component video (DVD player possibly), try that to rule out your TV set.
You might try getting an Xbox VGA cable ($40USD) and using that. Your TV has a VGA port and it should look just as good. Try to avoid the third-party cables as they are notoriously poor quality.