Hi, thanks for the interest, any help greatly appreciated.
A little water was spilt on the case and through a chasis fan when the power was off. 48 hours later on attempting to boot, nothing.
All details are here on a post I got little response to unfortunately. http://www.tomshardware.co.uk/forum/310151-12-lights-fans#t2082108
I've tested all outputs from the power supply with a volt meter and found them to be exactly normal. Re-sited everything and exchanged the ram. If you know the board, the power and reset buttons light, but no reponse on pressing power. No fans/beeps etc.
I'm changing the board out of desparation for what else to do.