New system build will not boot or post!!!

I brought all new parts to build a new system ..upon assembling it when i went to power it up it will not boot nor post ..my keyboard lights flash on then off and the light on my optical mouse comes on ..non of the fans spins and the front panel lights dont come on ethier...i have tried to remove the memory and boot to see if i get any post beeps but none..i think it to be eithier a motherboard failure or a cpu failure.. tho i lean more towards the cpu...are these syspmtoms of cpu failure?.or am i doing something wrong?.. also the screen shows nothing ...the PSU fan does not spin eithier...