Sorry to be on the other side of this, but I know what I am talking about. Please spend some time to study the subject and you will also begin to understand and agree with what causes plasma TVs to buzz. You will also understand that nothing is left loose or has a bad coil that causes buzzing. This is simply the physics of how plasma panels operate and they all buzz the same, unless less light is output. The luminance level dictates the dB of the buzz, which is why F8500 buzz more than ZT60.
Most folks can't here the plasma buzz as the FQ can only be heard by folks under 35 yrs old and with excellent FQ range hearing. The sound wave is very narrow and direction and is best heard from 4 to 12' directly in front of the TV.
That sound from driving the plasma is what you hear on a properly designed and built set within a foot or so of the front, so I am not disputing that it makes a sound, I am talking about how loud and the range and the plasma sound is unlikely to be the cause of the sets classified as "buzzers".
If it was the plasma no would ever be "fixed" and yet we see time after time of someone returning a buzzer for another set of the same model and getting one that does not buzz, sorry manufacturing quality and designs are subject to all kinds of flaws but physics is physics so if it as you claim, the physics of it, everyone would have a buzzer and we clearly don't. I have 2 pani 50" and this 64" Samsung and not a buzzer in the batch.
So perhaps you are mixing the normal operating sounds heard is a foot or so radius with flawed sets you can hear from 8 - 10 feet or more away, I can 100% assure you that is a defective TV or cheap and poor design.