spooky

Hi - Maybe not a Xbox question but I need some technical AV guru help PLEASE!

Just got a new Xbox 60Gb. In the box I have the standard connection cable with the TV / HDTV switch on it. (TV goes to the Yellow video Red/White Audio and the HDTV goes to RGB)

My screen is a NEC 4000 LCD (bit old) I set it up using the Yellow phono lead. But my screen has 5 BNC connectors. RGB but also H & V.

I've bough some BNC to Phono adapters. So I have put in the RGB connectors into the adapters but when I go to the RGB input (there are 3) I only get a Green image.

If I then go to my HD / DVD input I get a picture, but i'm not sure if its better than the Yellow phono connector. Likewise the Green screen I get does look clear, just green (ive tried all the adapters / fault finded and they all work)

My question

1. Is RGB the same as HD? Will I get HD quality using the RGB into my BNC connectors?
2. What are the H and V inputs (the 4th / 5th bnc connectors)
3. why do I get green only?
4. why doe it then work on the HD / DVD input
5. whats the best solution I can get with the kit I have (I dont want to get a new screen!)

Cheers for the help, please move the thread if its in the wrong place!

I know theres a techie out there waiting for the challenge!