Gen 7 1.5 problem

Hi I am making the Gen 7 1.5 board for a cnc router

I am up to the stage (as per the instructions on the wiki) where you short out the earth link and the pin on the top right of the Atmega socket.
The PSU should activate, which it doesn't, just hisses for a second and the led that should be on just blinks once then goes off

I am still getting 5v from the right places in the Atmega socket

Not getting anything at all from the 12v plugs or the pololu sockets

Jumper in the atx slot (top one)

Solder looks pretty good

Some of the leds are not the right size and the choke is a different type but still a ferrite core and the right rating

Thanks for any help, much appreciated

On a second check the IC socket is giving 5v without the psu activated so it just comes on then goes off when shorted, I am thinking its shorted across the solder, power is building up in the power supply when activated than it switches of automatically

problem fixed