Take your entire set-up out of the case and connect it on cardboard, wood or plastic.
Try reseating the memory and the cpu.
Try putting one stick of memory in the slot farthest away from the cpu. See if you can boot the board then.
Try booting with no memory or with slow DDR2 memory.
Try to see if you have the cpu fan connected correctly, and if you havent mixed around any +- ends (goes for USB, power connectors etc. as well).
See if your jumpers are all set to default (check the manual for default values).
Try to remove the motherboard battery, switching the jumper caps for at least 10 seconds and then back, and put the battery back in.
If none of this works, have your vendor test the motherboard or the whole system.