No display output while 6670 is installed- AMD A6 Build

Finished putting a dual-graphics build together, but it will only output to display from onboard when the 6670 I bought is not installed. As soon as i shutdown, install the 6670, and boot up is won't output to my display via On-board VGA or the 6670's VGA and DVI-D connections. Case, CPU, and 6670 fans all spin up, and DVD/Cases power and HDD lights work. No funny smells, arcing noises, nor pop music have been produced by the computer
The motherboard has previously had a nvidia 550 ti installed without a problem.

What I've tried:
-To change bios setting for display initiate to IGP (no crossfire), IGP (crossfire enabled), and PCI Express
-To update the bios to latest available version and then all of the above
-To restore bios to default before and after bios update
-To use a dvi-d cable instead of a vga to connect the monitor
-To get drunk and forget about it


Build is:
an AMD A6-3500
4 GB Crucial 1866 ddr3
Intel 335 240 GB SSD
ECS A75F-M2 (F1)
Rosewill 600 WiFi adapter (PCI 1x)
'Frisby' 350W power supply/ case
Lite-On DVD Burner
Gigabyte 1 GB 6670 (GV-667D3-1GI
Uber-super-mega-edition DELL SE198WFP 19" monitor

This build should stay far from any wattage shortages when overclocked,
running stock settings since I've gotten it

I expect to have to get an RMA on the card, since the power supply should be sufficient and the pci express slot has work on another card, but I'm just throwing the issue out there if there's something i haven't thought of