all i know to tell you is to start over from the basics in case you missed anything. first reset CMOS by doing what this video shows at 1:30
https://www.youtube.com/watch?v=rdHH9KrceR0 then...
Step 1) Remove all graphics cards, RAM sticks, hard drives, optical drives, and USB drives.
Step 2) The only cables coming from your power supply that you need to have connected to the motherboard are... 24pin atx power connector, 8pin(sometimes it's 4pin) cpu power connector.
Step 3) The cables that you need to connect from your Case's front panel to the motherboard are... HD Audio cable, and the assorted cables that go to JFP1 header on motherboard(look for this in your motherboard's manual, and do it as labled.)
Step 4) Connect CPU Cooler to the CPU Fan header on motherboard.
Step 5) Insert only 1 RAM stick into the correct slot that is listed in your motherboard's manual. (Do not just stick it in the first slot, that is not always where it goes.)
Step 6) Install the display cable you will be using into the display port on the motherboard's I/O panel. Install your keyboard. Plug in power supply, and turn the switch on.
Boot up the PC... you should either be taken directly into the BIOS, or get a prompt on the screen.