first pc build problem

i recently finished my first pc build, however i am having power troubles, the computer wont come on by pushing the power button, the only way it will come on is if i jiggle the wires in the area where the front end power and usb cables plug in

 

Sounds like a loose wire problem with the case if so take it back and tell them to rebuild it aswell for wasting all your hard work

 

Perhaps a lead or wire at the power-on switch is not connected.
You could disconnect the power at the wall socket (just to be safe) and remove the power-on switch leads from the mb and ohm out the leads and switch.
The meter should show that the switch is open (infinity) until you press it and then it should show closed or very few ohms (nearly zero).

I think the power-on switch works by momentarily (or longer depending on how long you press on the switch) shorting the two pins together and causing the mb to signal the psu to "turn on".

I don't know what jiggling the wire is doing; it must be causing a momentary connection between those power pins on the mb somehow. I would make sure the power-on switch is good.
Have you removed the switch from the case to look at it or can you see it with a flashlight to verify the wiring is firmly connected?

That's what I would do at this point. Perhaps someone else can second that for you or correct me if I'm wrong.