Without the CPU the Computer turns on and instantly off again.
Are you saying you powered on a system with no processor installed? I would think that's a good way to damage your board.
Try a different power supply. There have been several reports of power supplies that do not work with the DP67BG. Antec True Power was one of those.
AS Far as PSU Look at SeaSonic, Go to the web site and see what they recomend, They have the best active power control on the market , I would look at the 850 watt Gold Cert.
Powering on without CPU is probably a pretty poor idea. Not sure what that would prove?
I have a Corsair 850W with the DP67BG and no issue. Did you plug in all power cables on the motherboard correctly? There are two that should go from your PSU to the motherboard. You also have to connect a fan to the CPU fan header or it will not post.
I would say it is very rare for a motherboard or CPU to be shipped defective, and your PSU shouldn´t be an issue. I also run 2x4GB corsair mem modules on my one so probably not those either.
Your first build?
I can confirm that the DP67BGB3 is not working with the batch of Corsair CMPSU-750TXV2 that I have. However it works with the older CMPSU-750TX.
Mine work with a Corsair HX620 even though that model is not listed as being compatible.
On a side note: when is the new B3 revision of the DP67BG going to be available at retailers?? You cannot find them at any of the major retailers (NewEgg, Amazon, Micro Center, etc.). I wonder what is taking so long? Every other P67 and H67 board that was released back in January for the Sandy Bridge launch has been available for a couple of months or more at all retailers. The DP67BG is nowhere to be found...weird.