computer making strange buzzing noises?

[Eye of the Tiger]

i have been having issues with my dell computer almost since i got it in march 2012, its still under warranty, i have been hearing buzzing noises as well as grinding noises in various areas

the dell tech i talked asked me to see if i could isolate the sound so i opened it up and tried to, but i really cannot

i am fed up, i think i am gonna DEMAND new one or a refund, i have had techs out here to replace various parts almost a half dozen times and it still isn't right

http://youtu.be/OjvCeDLFhv0

note: turn your speakers up to hear it, the video does not accurately convey how loud it is, i heard it with my speakers up pretty loud. it is intermittent, about ten minutes after i made thsi video it stopped as suddenly as it appeared.