Bad memory chips or something else?

So I'm looking for some encouragement and some advise if anyone has a suggestion.

This is my second build. My first one was four years ago and went just fine. At the time, everything was new, and I was able to plug and play without any issues at all. Now that my PC is getting long in the tooth, I've decided to upgrade many of the components. The case, PSU, video card, and SATA HDD are the same as my old build - so as far as I know, they are known good components. I purchased an ASUS P6T motherboard, an Intel i7 920, a Corsair liquid cooler for the CPU, and a set of 3 1GB DDR3 1333mhz DIMMs from Crucial (they are on the ASUS approved vendor list in the manual).

I spent a day taking the old one apart and putting the new one together. Power on - no POST. Then I start to troubleshoot for the next few weeks. I get the no memory beeps when I remove all components and DIMMs. I've tried a single stick of RAM in every slot and each of the three sticks on their own. Any time I have a stick of RAM in place, I get no sound on power up. The fans spin, the lights turn on, the DVD drives spin, but no beeps to indicate no VGA detected. I've called tech support twice, and have since RMA'd both the motherboard and CPU with the same symptoms each time. I've worked through the no-POST-steps-to-do-before-starting-a-thread without success. The one thing I haven't tried is breadboarding. I don't think there's a short because the standoffs, motherboard tray, and case are the same as my old ATX build. I've tried resetting the CMOS several times with no luck. Never any video output or no-VGA beeps.

The one thing that has changed, is that I've had to swap out the 4-pin CPU power cable for the 8-pin one on this new board. Could my 8-pin socket on the PSU be dead? It's a 500 watt PSU. If it was underpowered, it would at least be able to POST with no drives, right? Is my liquid cooler sucking up a bunch of the power? The only thing I can think of is that maybe all three RAM sticks are bad and any time I put one in, it prevents the motherboard from getting past the memory check to the VGA check.