Specs:
CPU-FX8350
PSU-EVGA Supernova G3 750w
MOBO-ASUS 970 Pro Gaming Aura
RAM-Corsair Vengeance Pro 2133 2x8gb
GPU-ROG Strix RX480 8gb OC Edition
SSD-Scandisk Ultra II 240gb
HDD-Seagate Barracuda 2tb 7200rpm
Case-NZXT H440
Ok...so Ive posted nearly everywhere and to no avail, Im a smidge stumped! Heres the issue.....My PC gets RANDOM no signal boots! Some days it boots on the first try others it takes 3-4 times and sometimes more! When it takes too many tries, I either reset the jumper or pull the CMOS and poof! It Boots!Never once has it given no signal after the bios reset! My Bios is set to default and the no signal was pointing me to my GPU, and Ive ruled out my GPU as over the holiday I had access to my sisters rig(she has the same GPU), swapped mine in and it never once gave no signal, LEDs flashing, or VGA LED on the board staying lit! 50+ reboots/restarts and the problem never showed! Just for giggles I put my GPU in my dads rig as well and 20+ boots/restarts and no issues! See on the no signal boots, sometimes the VGA LED stays lit and I get no signal, others it just gives no signal and I can hear windows login chime in the background, and others I can let it sit for a min or two and it will give a signal! All those are at random..there's no pattern to it! When using my PC it performs as it should! Can game for hours, temps are great, my GPU/CPU performs up to spec, all voltage looks good in HWM! Ive benched and stress tested and it all checks out! I just want to find out the culprit, I have no other psu to swap out, and no other board, I can get access to RAM but I doubt its the issue although it could be! The reason I suspect my PSU is because when I was trouble shooting I noticed my PCIE read at x8 2.0 rather than x16 2.0, now I know this could be from a power saving issue, but windows is set to performance and all settings were set to not power it down, I changed the power cord on my Supernova to an older one I had laying around, and poof..It read as it should x16 2.0! Yet I still get the no signal boots! Im literally pulling my hair out lol...I thought it could be my memory settings but nope, UEFI/Legacy issue nope etc etc, Again It may not happen all day or it may happen on every boot/restart! But it does happen about 1 out of every 3 boots on average!  Did I miss a setting in the bios for my rig?? Ive tried with one stick of RAM, different slots, default bios settings, non-default bios settings(DCOP Memory profile). Checked cpu pins, unplugged all unnecessary hardware, 2nd HDD as well! Any help would be of great appreciation!

Wish that was the case...was the first thing I tried! Problem still happens when using HDMI or VGA!..forgot to include it in my description sorry!

Im on Windows 7 Pro, already tried the fastboot settings..no change...graphics are set to pcie only as well, the default is that in the bios..auto isnt even in the bios settings...I dont think my card will fit into the bottom PCIE slot, very tight fit(NZXT H440)but ill try, would rule out the PSU immediately if the problem goes away! Besides that the problem started on the bios that was previously on the board that came installed from asus...Im up to the latest...but maybe I should start with the earliest and work my way up!Also come to think of it, this PC is all brand new as of march/april of this year, the original liquid cooler I bought was the NZXT Kraken, I do remember assembling everything and installing windows/software/drivers etc and had to restart 1000 times for all the software I was installing and didnt have the issue...however i did have to RMA the Kraken as when my pc went into sleep mode a couple days later when i was in the shower (forgot to disable sleep) upon waking the Kraken shut down, LEDs and all and on the reboot the pump was  dead! So I went with the Corsair H100i V2 instead and come to think of it thats when the problem started! Maybe something shorted?? I just had a brain fart on that one sorry...I never thought that may have popped something on the board..But my Corsair functions completely amazing! Ill try and get my GPU into that slot..if not ill have to pull everything out to do it and report back!

Ok so I was able to get my GPU in the x8 PCIE slot and I got no signal on the very first boot! So again Im at a loss..To answer CoolGTX, Ive swapped monitors, used VGA and HDMI and the problem persists and all settings are set proporly on the monitor! Changing settings as you describe didnt work either! As usually i dont use any settings but default with DCOP profile for my memory! But gave it a shot and it didnt work! The very last thing Im going to do is flash the release bios(1st one) on the board and work my way up! Ive also noticed after I went to the latest bios the frequency of the no signal boots increased....Im quite sure that if flashing the bios again doesnt fix the issue I have a defective board...but I just wanted to rule out PSU or MOBO so I dont RMA the wrong thing as both are under warranty! I may just buy a new board and RMA this one and when it gets back keep it as a backup!! ASUS can take ages! The board isnt expensive! lol