iMac 2012 High frequency noise

Apple replaced my imac with the noise 27" late 2012

hi there
i had this really annoying high frequency noise - many thanks to ithomas for his temporary fix - after speaking to Applecare they suggested a replacement and it arrived today - i have been using it for 4 hours and let me just say the only noise i can detect is my lil western digital hard drive next to the machine - the machine itself is super silent - there is not frequency noise what so ever - its almost like working on an IPAD - NOOOOO NOISE !!!!! - Im so glad I went this route - one thing I learnt as I was restoring the old machine to hand it back is that ithomas's FIX works EVEN after you erase the harddrive and put a new operating system which is just brilliant however upon doing a PR RESET after that the sound comes back on - so good luck everyone and ty all for your input on this matter especially ithomas - without his help i would have been truly lost so cheers

thank you iThomas

I had the same exact problem everyone described, right out of the box. Some high-pitched coil-whining-like noise. At first I thought it was strictly because of the unfiltered or "dirty" AC from the wall outlet. I tried a few sockets without any luck.

Then I tried iThomas' solution and it worked! Although it's a great temporary solution, I'm wondering what I should do next, did the replacement unit work out for those of you who ordered a new one? I waited multiple weeks to get my hands this iMac and I don't feel having to part from it right now.

If you're wondering I have a brand new
late-2012 27" iMac
3.2 GHz i7
16 GB RAM
GTX 675 MX

same ol' same ol'

2014 now and after dancing on the edge of insanity with the whine I finally found the forum. How does one determine how widespread this is? I dropped over $400 a year ago for a new HD and video hard and a year later I am staring at a logic board replacement. Where are the lawyers?