Hmmm.... well, I was indeed a pin off on the cable which attaches to the board, so it now turns on. Huzzah! But, it doesn't get much further.... I can't hear any hard drive action, and after showing the boot animation, it just hangs here:

<img src=http://yoyo.its.monash.edu.au/~blipman/trash/empeg.jpg>

I assume something's still not right with the cables, or should it not even get this far if that's the case?
Confidence in my skills falling..... falling..... gone.

Ben