So I built a new PC from a dell optiplex 9010 motherboard with an i7 3770, 16gb ddr3 and a gtx 660, and recently went to upgrade the gpu to something with some more power. I bought a used Windforce R9 280x that was assured to be working (still unsure) and plugged it in with the necessary power inputs (1x 6-pin and 1x 8-pin). On first boot every thing powered up, even the GPU, but for some reason there was no display. Thinking it may be something to do with the Nvidia drivers and the AMD gpu but have done research and that should only affect things once you're actually using the system in games and shiz.
Someone help!!!
Someone help!!!