So, I recently bought a gtx 750ti(was using it with an pci riser because it was 2 big 4 my prebuilt case) and installed it. 24 hours later, and the card doesn't show up any image, I tried with my old working GPU (r7 250) and when I plugged it into the slot and powered on the PC, the fan moved for a little and then stopped. I had to plug the r7 250 back in so I could get the fan working, but no image whatsoever of both cards