Motherboard/ram issues?

[Troika]

Ok, so, I know the motherboard was working as of 10 minutes ago. I pulled the graphics card off then plugged a different one in and suddenly, no post. Its an old Asus Crosshair II so maybe I moved something by accident. I took everything off then turn it on with just cpu and ram in. No post. Ok, I took the ram out to see what would happen. I got a post error, clearly the board knows that there's no ram. I go through the tedious process of checking ram and ram slots individually. It posts on all of them. Ok, so I occupy all the slots and turn it on. The board posts. Cool, plug the gpu in, hard drive and sound card. No post. Ok, take things off one by one. Gpu, no post. Sound card, no post. Hard drive, no post. Just ram and cpu, no post again. I'm at a lost. What exactly is going on?

[Troika]

Computer specs

CPU: AMD Phenom II X4 940 Black

MOBO: Asus Crosshair II Formula

RAM: 8GB 4x2GB DDR2 800Mhz

GPU: EVGA Geforce GTX 570 1.25GB

PSU: EVGA Supernova GS 650w 80+ Gold

HDD: 1TB Seagate Barracuda

OS: Windows 7 Home Premium x64

[Troika]

Ok, I'm pretty baffled right now. Has anyone else noticed that a liquid cooler would prevent a computer from posting? Or is that a specific problem with older hardware? The cooler in question was a corsair H110i GTX. I had swapped the crappy AMD stock cooler I had after noting that my temps peaked at 70C during 3dmark. I had my H110i leftover from the gaming computer I parted out. I had decided to keep it until I could get a better air cooler to use on my phenom II 940 but it seems like it prevents my computer from posting but... why is that? How could a liquid cooler affect a computer's functionality outside of cooling?