Motherboard cycling power on and off

Hi guys, if you could lend some advice I'd be really grateful. I'm a total newbie, this is my first time building a computer. I thought I had everything together correctly, but my motherboard does the dreaded endless power loop cycle no matter what I do. Here are my components:

Intel Core i7-3770K Ivy Bridge 3.5GHz (3.9GHz Turbo) LGA 1155 77W Quad-Core Desktop Processor Intel HD Graphics 4000 BX80637I73770K

XFX Double D FX-787A-CDBC Radeon HD 7870 GHz Edition Black Edition 2GB 256-bit GDDR5 PCI Express 3.0 x16 HDCP Ready CrossFireX Support Video Card

MSI P67A-GD80 (B3) LGA 1155 Intel P67 SATA 6Gb/s USB 3.0 ATX Intel Motherboard

NZXT Phantom PHAN-001WT White Steel / Plastic Enthusiast ATX Full Tower Computer Case

Rosewill CAPSTONE Series CAPSTONE-750 750W Continuous @ 50°C, 80 PLUS GOLD Certified, Single +12V Rail, ATX12V v2.31 / EPS12V v2.92, SLI Ready, CrossFire Ready, Active - PFC Power Supply

Western Digital Caviar Black WD5003AZEX 500GB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive - OEM

CORSAIR XMS3 16GB (2 x 8GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CMX16GX3M2A1600C11

I hooked the motherboard up to ram, cpu, cooling supply, video card, and HDD, but it does endless power loop. I removed everything down to bare bones -just PSU, cpu, and cooling supply, but it still does endless loop. I
tried removing all of the ram - same thing. I also tried doing the
CMOS_CLR - still endless loop. I tried using an old power supply known
to work fine, and it still does endless loop. I tried removing the
battery and reinserting it, still endless loop. I pulled all the case
cables out, but it didn't help. That's all I got - people here at work
think it's just a bad board.

Does anyone have any advice before I RMA this board? Please let me know!