Computer not booting, cpu black dots?

Hi there, i recently purchased an i5 3570k off of ebay. I also bought an asrock extreme 4 z77 motherboard for it. I testbenched the system with just mb and cpu, with and without ram, with and without a graphics card. And everytime i turn it on the fans spin and continue spinning but nothing else happens. My monitor display a no signal message at the same time, i also hear no beeps when the computers on to indicate a error.

I tried hdmi out, vga out, and the mini hdmi out on my gtx 460, the psu isn't the problem because im currently using it on the pc im on now, i got told to check the motherboard pins and everything seems fine (although when i first opened it a heatsink was half off and the push pin was missing, although thats fixed now), i also checked the cpu, and found a couple of black dots on some of the gold connectors, i am wondering whether these are burn marks. too my knowledge it hasn't been overclocked and the original heatsink that came with it had the original thermal paste on.

I took a close look at the marks and they look more like just dirt rather than burn marks, but i am wondering how do i test to see if its burnt out? and if i can clean it? and if that isn't the problem then if i should return the motherboard and get a replacement? Thanks in advance