That seems to suggest a CPU issue. Do you have access to another CPU or, better, another motherboard? A friend willing to let you pull their system apart?
I've had this issue before. If you tested each stick of ram and you believe they are working, test it on a diff mobo if available and use Memtest.
Try to test the cpu on a diff mobo as well.
If all possibilities are out it may be the cpu or mobo itself. I ran into this issue before and the actual pins on the mobo where you lock down the cpu were bent. of course this was my fault... Newegg was kind enough to Rma the mobo due to the large purchase made. (usually they don't let you rma due to consumer dmg) This could either be a maunfacturer error (not usually cause there pin straight) or.... when installing the cpu it wasn't placed in straight or perhaps you lightly slide it... whatever the case maybe they might be bent. Check it with a flashlight and see if all pins are exactly the same.
Ok, so I looked at the cpu and mobo. All the pins look fine.
I swapped out the Hyper Evo 212 for the stock intel, because the ASUS support indicated it could be a problem with the fan.
Now, when I try to boot, i get one beep followed by one additional beep a few seconds later.
I don't have access to another CPU or motherboard.
Have a good application of thermal paste? Too much wont boot.... too little wont boot. Need a very thin application where its almost metal to metal contact. I use the pea size in the middle and then bake for 48 hours.
If you can't test them, your troubles do lie in either the CPU or Mobo. Best bet is to RMA both just to rule them both out. Thats my opinion, I wouldn't wait to receive 1 rma just in-case it was actually the part you were holding on to.