Alienware 17-R3, buzzing noise

Hello, since month I had a buzzing noise problem when something was going on on the screen. It starts only with the adapter and when I move around icons for example. Then no matter what happens on the screen the noise is there, then even without adapter, the buzzing and other clicking noises are there... Finally I was getting fps drops during watching movies.. playing games... so I contacted dell support and they changed my motherboard, graphics and processor obviously. The noise was still there, altough only with adapter. I called DELL again and requested a new A/C adapter, because I had 190W and thought maybe it was the problem, they gave me the 240W adapter and THE PROBLEM IS STILL THERE, what the is going on with this..... what u people think.. Obciously I tried things like unpluging everything,, reinstalling windows over and over, all drivers, newest, older versions, I checked this in the other room if the noise will be there, and it is.