New Computer not starting

Started to build my very first PC yesterday. I connected the CPU, Motherboard, Graphics card, SSD, and RAM outside of the case to see if any of the parts were dead and the system turned on (the screen I turned it off at wanted me to press F1 to continue to boot if I remember correctly). However when putting everything into the case and putting it altogether, the PC only stayed on for two seconds before turning itself off and then wouldnt turn on at all unless to I/O switch was turned off then back on. Any help in trying to get this to work would be greatly appreciated

The mobo is probably doing some contact with the case, and causing it to short and turn off.

Did you install the motherboard correctly using the  all standoffs?

I connected the standoffs, but now it's not turning on at all. I ended up using 7/9 since there were only 8 spots and the one on the topr right didnt have a hole to line up with. Praobably should've put this down before but, my case is a Fractal Desing R4 and the motherboard is a ASRock Z77 extreme 4

try to take out the board, and takeout the io shield, then try again, probably the lips of the io shielt make contact with the mobo, probably you didnt put the board in the right angle, to the io shield.

Is the PSU actually switched on?

Sounds like the short-circuit protection kicking in. Did you do any cabling in twist-and-tape-technology? On a fan maybe?

The PSU was switched on. In fact it was the only way to turn it on initially

No I only used cable ties for management

It's not touching the I/O, but it is at an angle and hitting the back side of the case after putting in the standoffs'. I'll try removing it again and see what happens

**The I/O doesn't have a shield. Just realized :p **

I believe that this was the same problem that I had at first, before I fixed it. You know all of those small cables labled "LED" and "POWER SWITCH"? They're supposed to go in vertically, not horizontally. I know this is a little common sense, but I didn't know this when it came down to my first build. Hope this works for you as it did for me.

So I decided to breadboard it again and it works perfectly so it's definitely something regarding the case that has it stop working

I dont think that would cause it to not turn on at all though. Also my manual has them displayed as being horizontal

take a screw driver to the two power pins, unless that's what breadboarding it meant

Whoops sorry. I think I used the term wrong. It was directly connected to the power supply. Took everything out of the case, connected it, and it worked just like before. A blue screen came up with some stuff and at the bottom had "Press F1 to continue"

if it works out side of the case you have a short take your stand offs out and re-check / re-do them, this or your not pluging in one of your power cables GL (post pics if your still stuck)

Did that and strangely enought it worked after taking it all out and putting it in again. HAving trouble with my case fans not starting, then again trying to use four fans through one molex adapter may not be the best idea lol. Thanks to all of you guys for the help!!