I built a PC a month ago, and until today I have had 1 beep after the startup POST test. Today, it started beeping twice, very quickly. I looked up the beep codes on Asrock (the mobo manufacturer's) website and there was a list of them, but nothing for two short beeps. What could this be? I was told it might be RAM, but I ran Windows Memory Diagnostic and that came back clean. I even reseated the RAM and that didn't help anything. What else could the 2 beeps mean?

Specs: Windows 7

Asrock z75 Pro3 motherboard

Intel i5-3570k

GTX 760

600w PSU

EDIT: One other thing I forgot to add is that a day or two ago, when I was adjusting a wire in my case my hand hit a GPU fan. It threw it off balance and dented the heatsink in the GPU a tiny bit, and has since made a slight buzzing noise when it accelerates, but it has run fine. That may or may not be related, I wouldn't know.