I have built my own computer using an ASRock H87 Pro4 motherboard and an Intel Core i5-4590, with 4gb RAM. When I first built the computer it worked perfectly but now I have bought a EVGA GeForce GTX 750 ti gpu and installed it into the motherboard. I had a little trouble getting it in but it does seem to fit. When I turned the computer on, it made a lot more noise than it did before and turned on. I tried to install the gpu drivers but it couldn't detect a gpu. I then plugged my HDMI cable from the monitor directly into the gpu, but it didn't show up on the monitor at all. Do I need 2 HDMI cables or have I done something wrong? Also, I couldn't find a slot for my 6 pin PCI express cable on the gpu.