I was asking to confirm if you have integrated graphics or not. Unplug the GPU from the system and connect your HDMI or other video cable you are using into the motherboard IO then try to boot the system. If it works then it might be an issue with the card. if it boots then the next thing you want to do is confirm if it's the card or if something happened to the PCIe on the motherboard by plugging your previous card into the system and booting with it. If you can boot into windows without a GPU and with the 970 then it's the 1080 that's bad. Report back with your findings of what works and what doesn't.