Build Advice New build. System powers up for 3 secs, shuts off, powers up, repeat.

Mayers90

Distinguished
Sep 6, 2013
4
0
18,510
Hi folks, I realise this kinda thing has been asked previously but the specifics of my situation has me stumped and I'd rather ask.
I'm building a pc for a friend. All I have installed is PSU, CPU, motherboard and ram. The PSU is brand new and the motherboard came from my own rig, as I upgraded and was working fine just 2 days ago in my own.
As the title suggests, I'm not even getting to POST. I've tried reseating the ram (and removing it entirely). I've tried it outside the case too, same thing happens.
Since my own PC is 30 miles away, I can't swap anything out. Any suggestion would be really appreciated. Sorry if I'm missing useful info, I just woke up lol.
 

Mayers90

Distinguished
Sep 6, 2013
4
0
18,510
Oops duh! These are the only parts in place right now.
450W CV Bronze PSU
Gigabyte ga-h81m-s2pv
i5-4570
Cooler Master Hyper TX3 EVO 3
1x4GB corsair ram (can't remember specifically which)