Originally Posted by Hockeytown Fan
does anyone really know what cause the "plasma buzz"
Yes and No, really.
Its been a wide spread "issue" will all the manufacturers and every years different models but it's never exactly the same. Some buzz is "normal" from the plasma charge / discharge cycle but this is nearly in-audible. Never the less manufacturers use this as a blanket excuse that "all plasmas buzz".
In my opinion, after reading the entire internet, the problem's root cause is magnetostriction in components of the high voltage power supply. Where this gets more complicated is that these vibrations appear to find secondary "loose" components that also begin to vibrate at harmonics of the original frequency. The individual inductor may be vibrating on the power supply board, some other component may be vibrating on the board, the board may be vibrating on its mount, the mount may be vibrating, a loose board nearby may be vibrating, trim pieces, wires, straps, nuts, bolts, screws .... the entire TV .... may be vibrating
The key offending part appears to be the power supply. I think if the individual components are "quiet", properly mounted, and the board is adequately mounted with vibration isolators then 90% of this buzz would never happen.
I completely fail to understand why the manufacturers continue to ignore what is probably the largst complaint with the entire industry year after year after year. At this point (what, 12'th ... 14'th generation ....) I would be embarrassed to put sets on the market that have this issue and show how ignorant my engineers are.