Hey. So as some of you already know, i'm one of the people who got the iMac yesterday (1st Feb). Opening the box got the heart pumping like crazy, and when i put the iMac on the desk and took off the grey thingy....breathless...took almost an hour to compose myself lol. At first glance everything was OK, no weird sounds, no yellow, nothing. I thought to myself, "yeah!, perfect machine!!". BUT...dind't last long. As i dim down the brightness (i like it about half bar of brightness) there it was, a high pitch sound grinding my mind driving me near madness. If i keep it full brightness everything is fine, as soon as i dim down the high pitch sound starts, when it's at minimum besides the high pitch there is a electrical/static kind of sound on the top left side. (Cricket like sound lol, I think the iMac's are being made in a jungle somewhere, cat piss on the screen, and crickets on the imac) I turn it off, turn it on again, change the plugs in the same outlet extension, a different plug in the same room, but nothing, the buzz was always there. After searching about the subject i've found a program "Shades", it resolves the problem, but, the problem will be always there. The question now is. It's more than within the 14 days returning period, do i send it back for a replacement, wait 2/3 more weeks and the possibility of receiving another with the same problem or a yellow tinge/flicker, or do i stay with this (which the only problem is the buzz sound) and ask them to repair? I'll be honest, I do not know how it works customer support here in the apple Portugal, i don't now how flexible they are lol. When you get home I'll use it again and I will leave it connected to see what happens tomorrow and I call the customer support apple. For the rest of you who also received the iMac yesterday with no problems, congratulations it's a damn mean machine Will keep you posted!