I just installed an executer 2 pro (red board with SMD chips) and the soldering/joints are all perfect and verified. For some reason the Xbox doesn't want to boot up. The power lights comes on for .5 of a second and then power cuts out. It refuses to boot up. I have installed a few of these without a prob, except now

Any help would be much appreciated

Does the system boot fine when you have the chip either unplugged or turned off?
If it does then it's probably a chip problem. If the sysetm doesn't boot up then it's a solder problem. Recheck your points, maybe even restrip the wires and try again.