Have you tried the video card in another computer to make sure the card is OK. Plus the PSU is a little low on power.
I know the case that you are using, you will have a tuff time finding another PSU for it.
You have been lucky to get the video card too work at all in the first place.
Gigabyte-Ga-x99-UD4 i7-5820K 3.30Ghz G.Skill 16gb DDR4 2133Quad, His R9 290X IceQ X2 4GB, IN Win Glacier 900w Cooler Master HAF 932, 2-240Gb SSD Array Win7 Ult-64bit 39" LED TV
GIGABYTE-GA-990FXA-UD5R, FX-9370 4.4GHz AM3+ 8-CORE, Mushkin 8gb DDR3 1600, EVGA GTX 480-OC 1.5GB, Ultra 750W PSU, cooler Master HAF 922, Win7 Pro 64bit & Win-10 64bit - Play around with computer