mobo doesnt de

So, i want upgrade my old pc but my motherboard doesnt see gpu. I bought new gtx 760 windforce, fans work and when i plug in cable to my psu no signal disappears but i still have black screen.The monitor is in standby mode My specifications CPU: i3-2100 MOBO: Gigabyte ga-h61m-s2-b3 GPU: This gtx...