It really helped me out to clear the cmos... thanks brotherDoes it return to normal if put the 670 back? In case something was bumped?
Did you plug both pcie supplementary power plugs to the 2070?
Try clear cmos to reset bios in case 670 being a non uefi card is confusing the bios (shouldn't be confusing bios but try). With the 2070 in, disconnect main power and remove the cell battery from the motherboard for a couple of minutes. There's only one battery, looks like a coin. Remember which side it goes back in.
That psu doesn't seem like very good quality. Even if got the card working i wouldn't trust it. Research best psus.
It really helped me out to clear the cmos... thanks brother