Computer trips, and then doesn't? What?

Starbuilder

Honorable
Mar 1, 2013
1
0
10,510
Hey there folks!
Been aching to build my own PC for 3 years, so finally done it today! Woo! :bounce:
Now, here's the thing...
(First, my specs are http://uk.pcpartpicker.com/p/FTO8)
I set it all up, installed CPU, applied thermal paste correctly, etc, plugged everything in and sorted the cables. Fully knowing i'd got the components right. Cables, well, I followed all the manuals, so i'm pretty sure they're right too. Never built a PC before so it took me most of the day.
Now, being excited, I decide to just turn it on and check it all boots fine as a quick thought before putting the side on.
However... it didn't work.
Now, what happens is that it'll turn on for about a half a second, and 2 fans will attempt to start spinning, and then everything trips. Motherboard is still recieving power, however, the small digital display in the bottom will turn off, and the computer is effectively dead while powered. I have to switch it off at the PSU to turn it off.
Now, once, about every 10 times I try this, it won't trip. Fans will start spinning, all of them, LEDs light up, and it seems to work. So, I hook up the monitor, maybe I can run some tests on the actual system, I think, after installing an OS. But, I see no BIOS, no nothing, come up on the monitor. Once again, my lovely gorgeous PC isn't outputting. Simply spinning her fans, heating up slightly, and doing f**k all else.
I've checked connections, everything's in secure, but I don't really know what to do. There's no obivous problem, and I have no spare parts to play around with.
Suggestions? I'd prefer ones that involve not taking anything out first. I feel the more I play around with parts, it's only a matter of time before something snaps, or fries, or gets a shock. :(
Just so frustrated being so close yet so far!