I have an old Quadro 600 and it doesn't give output from display port on my b75a chipset lga 1155 board. My main pc has x570 chipset and it works just fine. I use the same cable and the same monitor. My screen is on but it's just black and it's getting no input and the source is switching between dp and hdmi. I can provide more information if needed. Any ideas on how to fix it?