I'm getting this weird electrical type noise from my refurb iMac (probably why it's a refurb in the first place). It sounds like its coming directly from the lower right of the computer. The best I can describe it as is a noise a cricket (insect) makes; it's a soft buzzing/ticking sound that increases in level depending on the CPU usage. It is heard most often when scrolling up or down a web page with lots of graphics and pictures. It also occurs if I open a large PDF document and scroll up/down. Another example; if I open Aperture and make it full screen and scroll through my pictures the noise will occur. The noise also occurs when the CPU usage goes above 20%. I have a SSD installed so it definitely isn't the hard drive. It also isn't the fans because I can turn the fans on high/low and the noise sounds exactly the same. It can't be the power supply because that is located in the top left and the noise occurs in the bottom right. I don't believe it's the LCD display either. Anyone else have/had a similar problem? I'm eventually going to take it into the Genius Bar once I'm totally driven crazy by the noise.