Been running a 1070 for a couple of years in my Dell Aurora desktop. 16 gigs of ram, 1 tb HDD, 460W power supply. Upgraded to a 2TB SSD, had to remove the video card to do that. Reinstall and I get a black screen. Check all of the connections and lo-and-behold I had connected the power cord wrong; it is a 6 + 2 connector and I had forgot to add the +2. I'm not sure which holes I slotted it into. Reconnected correctly but still black screen. Tried all display outputs, tried moving PCIE slots, nothing.
I ended up using the onboard UHD graphics, running over the same DP cable to my monitor, to clone the HDD and set up my SSD. Checked the BIOS, no settings to turn on or affect PCIE. The 1070 has fans running, but the system does not recognize it at all, shows nothing in the slot under device manager, cannot install drivers.
I find an old gtx 670 and plug it in to the PCIE slot. The system recognizes it, I install new drivers, it works just fine using HDMI.
So...PCIE slot seems to be working. DP cable and monitor working. Online wattage calculators say that I should have enough power. Did I screw the 1070 up by plugging in the power cable incorrectly?