Originally Posted by Webby 
Just had another thought have you tried attaching the extras volume/lcd etc when its out of the case? If you have and it boots then maybe the is a short when everything is installed in the case. Find the short solve your problem!
I was thinking about that. The problem was that the pc booted fine, but when i tried vista media centre i would only get a black screen or the application would freeze up. I think its more likely some kind of issue with the extra hardware - i suspect the card reader as when i first tried it the bios froze on discovering the card readers drives.
i spent so much time on it before i tried it out of the case that i dont know if i can face the process of trying to work out which part is broken!