Fans spinning, but no image and mouse/keyboard isn`t working.

[darkcookie]

So yesterday I turned on my pc, but there`s was no image on my display and fans was spinning really loud, my mouse and keyboard haven`t worked too. Than pc is restarted, but as I said before, nothing happened.
I powered it off and turned on again with button on my case, and I saw "American Megatrends" logo, which was saying that overclock is failed. I have never overclocked anything in my pc, and this really suprised me. I pressed F1, entered the BIOS and booted up my system and it worked perfectly until today. All this story is happened again. I fixed it the same way as I did last time, but this is really worrying me, because I don`t know what is wrong right there.
I didn`t changed anything in my setup (besides a little cable managment), what could be wrong here?

 

[scout_03]

recheck cable if they are all well plug in some thing could be loose even a part .