New Build problem: immediate restarts

[ashatron]

Hi all,

I'm having a problem with my new build.
It seems to be restarting after a few seconds, then starting up on its own randomly after that.

It also switches on if I tap the case!

Here's a video -
https://www.youtube.com/watch?v=WYeX77XVL0Y&feature=youtube_gdata_player

I've Checked all parts are seated correctly, I disconnected the power and reset jumper buttons from the motherboard, and the behaviour is still the same.

I don't think it's overheating as my heatsink is very cool and it can happen just a few seconds after being switched on. I've disconnected all hdds and same problem.

It also immediately turns on when I turn on my psu from its switch, but then switches off about 1 second later.

Here's the spec -
I5 750
Hyper cooler 212
Gigsbyte H55n-usb3 motherboard
Corsair gs600 psu
Crucial 2x4gb DDR3 1600Mhz Ballistix Sport Memory
Hitachi travelstar 2.5" hdd

I've no idea and really help someone can help!

 

[ashatron]

Thank you both so much, I'll try that.
The video is now public, sorry about that.

If the case is causing the short is there anything I can do about it? :/

 

[ashatron]

You guys are a bunch of geniuses!

You were spot on about the short. It was the cpu backplate which was touching a chip in 2 different places, so i cut it down slightly, put electrical tape on and its running fine now!

Thanks so much everyone!