No Power

[Mark24]

Hi, about 1 month ago i purchased new computer parts to make a new homebuild, installed the components, plugged it in, and pressed the power, nothing happened. The only sign of life is a led on the front of my case is on (no led on motherboard). I have already RMA'd my motherboard and PSU, and when i put the replacements in, same story (no power, just a led on the front). Im a little clueless about where to go from here or what to even check. Sorry if this is not enough info, if you need to know anything else about my situation feel free to ask. Hope you guys can help. Pretty sure everything is hooked up right, but up for any suggestions.

Intel Core 2 Duo E6420 2.14GHz Conroe Processor
XFX Nvidia nForce 650i Ultra Intel Motherboard
XFX Nvidia GeForce 7600GT Graphics Card
G Skill 2GB (2 x 1GB) DDR2 800MHz-6400 RAM
Sony NEC Optiarc DVD Burner
Western Digital 200GB Hard Drive
NZXT Lexa Aluminum ATX Tower Case
NZXT PP500 500W PSU
Zerotherm BTF90 UFO Silent CPU Cooler
Arctic Silver 5 Thermal Grease

 

[Solariscs]

You sure you plugged in the power button cables correctly?