My pc starts up then turns off (Watch video)!

[EvooBrudda]

http://youtu.be/5n6whwxNgv4 Here is the video, when i take out the motherboard out of the case onto the mobo box it starts to work but when it goes into the case it doesnt work!

 

[EvooBrudda]

Ive only connected the cpu to cpu and the 24 pin to the 24 pin slot and its still not turning on all the screws are in place but there is only 1 plastic screw thing and 5 metal ones

 

[EvooBrudda]

Its still not working it only works when its outside the case...

 

[EvooBrudda]

I think it might be the plastic standoff because when i shake it upneath the motherboars moves but
When i shake it undernath the metal screws it doesnt shake and its stuck so i think i need buy some standoffs do you think thats the prblem?

 

[EvooBrudda]

Is that a good thing? Or does it have to be screwed in heres another video http://youtu.be/0-JptLXohqU

 

[EvooBrudda]

Without the standoffs it still doesnt work...

 

[EvooBrudda]

Yes and its still the same problem..

 

[EvooBrudda]

Yhh ill love to speak to them but everything shut as ifs xmas eve.

 

[EvooBrudda]

I tried the psu on my old mobo and if
Works so it cant be the problem..