Build a PC PC build doesn't power on

Hi guys, I've spent today building a pc for myself. However, on pressing the on button there's no reaction at all. My machine specs are:

M/B - Gigabyte GA-970A-UD3
Processor - AMD 8270
RAM - Corsair 8Gb DDR3
Case - Zalman Z11
Graphics card - Gigabyte HD7870
PSU - Corsair CX750M (750W)
Wi-fi card also installed, but can't remember the name and seem to have temporarily lost the box in a pile of packaging

So far I've checked the CPU and motherboard power sockets, the wall plug sockets and the power cord to my PSU. I've also checked the connections between my case and the motherboard, and these all appear to be correct.

As part of this final point, I switched the power on LED with the power button (they both originate from the same location so thought they may be mixed up). Anyhows, I got a solid LED, which suggests to me that a) there's power running through the switch circuit and b) the pc isn't booting when told to, as a solid LED would indicate circuit completion,which would be the equivalent of holding in the 'on' button.

If anybody could shed any light on where to go next, I'd be eternally grateful (currently searching the house for a paperclip to test the PSU...).
 
A quick update - I've tested the PSU by 'jumping' it and it works fine, as do the attached peripherals. I've checked the mounting of the motherboard too and can't seem to find any sources of shorting or suchlike.
 
In the wee hours of this morning, I finally managed to get the build working.This followed removing all components and finally the motherboard from the case, and testing just the board and CPU. So, I'm guessing it was a short circuit, but I still can't see where. My best guess is this - there are two countersunk screws on the underside of the board that jut out a bit. The screws holding the motherboard in the case were extremely tight, so I'm thinking that maybe the screws were tightened enough for there to be contact between the case and countersunk screws.

So far, I've replaced the board, not tightening the screws up so much, testing along the way. This morning I'll be adding all the connections and then PCI cards. Fingers crossed it's problem solved.

Thanks for the help guys.
 

GhostRyder

TS Evangelist
In the wee hours of this morning, I finally managed to get the build working.This followed removing all components and finally the motherboard from the case, and testing just the board and CPU. So, I'm guessing it was a short circuit, but I still can't see where. My best guess is this - there are two countersunk screws on the underside of the board that jut out a bit. The screws holding the motherboard in the case were extremely tight, so I'm thinking that maybe the screws were tightened enough for there to be contact between the case and countersunk screws.

So far, I've replaced the board, not tightening the screws up so much, testing along the way. This morning I'll be adding all the connections and then PCI cards. Fingers crossed it's problem solved.

Thanks for the help guys.
Cool Good luck!