Comp won't boot, have I missed anything?

[Golden Dragoon]

I have just installed my new psu and mb (gigabyte x48-ds5) and it isn't booting, there are no lights coming on the motherboard with the new psu, or my old one, and the power/reset button is unresponsive, I have tried reseating all connectors, CPU and expansion cards. Reseting the bios, taking the batt out and leaving unplugged for 20mins, and removing the mb to make sure there are no shorts on my case, I can't see any and am at a loss as to why it is seemingly unresponsive no power, beeps, or fan activity at all.
Plugged in the old, and new psu into my old ip35 with an old celeron (tried in the x48 as well) and get power and gfx/mem error beeps (didn't install them) so they work at least as does the graphics card.
So is there anything I have missed or can try as am really hoping that the mb isn't dead.

[Sputnik]

have you checked that the case switches and led's are properly connected to the header on the Motherboard ?

If everything is ok maybe you have a DOA board?

[Golden Dragoon]

Actualy when I put computers together I use an old power switch from a obsolete case, hooking up the connectors is one of the last things I do, and I know the switch works btw used it to test the ip35

[switchmode]

I hope you do not take this the wrong way. I am trying to help. My experiance is that if you move things around a lot like your switch it is then a possible point of failure, just double check it is not the switch you are using.

[Golden Dragoon]

Don't worry it was actualy one of the first things I checked, just got back from work and will give things another try before I go to bed.
Edit: also I should point out I took anti static precautions during the build and through the trouble shooting steps I have taken.

Edit 2: Got it working now, the xfx psu I bought had 2 8pin cpu connectors, one in 1 block of 8 and one in 2 blocks of 4, plugging in the split one allows the mb to boot up, yet the single one won't, not sure if there is any difference between the two connectors as they both fit, and the xfx manual isn't any help, but am glad it is working now

[watercooled]

The solid 8 pin could be a PCI-E connector, but if that was the case I don't think it would have fitted, did you check it was definitely a CPU connector? Look at the colour of the wires compared to the split one if the manual doesn't help.

[Golden Dragoon]

The solid 8 pin could be a PCI-E connector, but if that was the case I don't think it would have fitted, did you check it was definitely a CPU connector? Look at the colour of the wires compared to the split one if the manual doesn't help.

it is listed as 8 pin EPS 12V connector, the split one is listed as 4/8 pin ATX 12V/EPS 12V the pins are the same (1-4 ground, 5-8 +12V), and I know that eps and atx 12V are effectively the same thing with differant names.

Edit: just looked it up, as I thought same thing really http://en.wikipedia.org/wiki/EPS12V

[watercooled]

I would say a loose contact could be to blame but since all 4 of each colour join up again at either end at least 4 would need to be loose. Was the connector pushed all the way in until it clicked?