I bought a new gigabyte 270x graphics card. After correctly installing it, both power plugs, correct pcie port, and a 750watt psu. I try to boot. All the case fans start, the mouse laser lights, the hard disk starts but the gpu is completely still, the fans do not turn nor does the display detect a signal. I am using a new msi 970a motherboard. There is no onboard graphics option and I don't have another card