I've installed my new ASUS R9 280X graphics card and all of its drivers correctly, but when I boot my computer, nothing shows on the monitor. I know the rest of the computer is hooked up correctly because if I remove the graphics card and boot without it, everything works fine. I am using an HDMI cord. I have an Inspiron 620 motherboard and it supposedly turns off onboard video off automatically (you cannot do it from the boot menu). I think that pretty much covers what's going on, but if you need more info let me know.