Danny - would love to try another system but sadly I don't have another to cross-check this one against. As for RAM, will try that. Right now, it doesn't matter which of the three sticks I use - no POST beeps at all, nor do I get POST error beeps if I power up the board without any RAM...
I decided to build a new PC recently after a period of not having built one other than minor upgrades. It will not POST at all any more. Components are as follows:
Asus P6T Deluxe V2
i7 920
x3 2GB Corsair 1333 DDR3
EVGA GTX 260
PC Power & Cooling 750W
What I have done a rough...