I have a Samsung HPN4239 that was making a very very loud buzzing noise. I found a page: http://wa6ati.com/Samsung.html, which suggested the " Install a felt cushion part number is: AA63-60122L" solution.
I'm not sure if you care or not, but I found an easier and cheaper solution.
I placed a small (about 1mm thick) plastic washer between the back cover-panel and the housing in the 4 screws on the bottom left as you face the HDTV from the rear. More detailed: Remove the main back cover-panel. Place a small plastic washer between the back cover-panel and the housing starting with the lower left corner (as facing the HDTV from the rear). Place one more washer under each of the 3 screws above it also. Replace all the screws.