My roommate ordered his PC from Amazon and it arrived today. We put it all together and tried to start it up, with the monitor plugged into the card's HDMI slot.. All the LEDs and fans come on, but there's no video on the monitor. Could it be that the card needs drivers to access the HDMI? What else could be causing this? We flashed CMOS or whatever. 99.9% sure everything's plugged in. For the CPU power we used two 4 pin connectors, is that good enough? The PSU also has connectors with 6 and 2 pins, right next to each other but the 6 pin says PCI-E so we just used the two 4 pin ones.