slap that reset bios button the the back of the i/o plate. my theory is that you have CSM disabled and the new vid card doesn't have the latest bios. so you're hanging on POST. Just my theory, wouldn't hurt to try it since you didn't state that you attempted it.
Also, what other steps specifically have you taken for troubleshooting?
-hax0rmort
MOBO - ASUS ROG Crosshair V Formula-Z
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