Hey there This is a problem similar to the one below but i have more details to add I noticed after a recent move my TV is making this horrid high pitched noise. After running through some quick trouble shooting i noticed it didnt make the sound when the Xbox 360 was running. My xbox is running into the TV using component. While trying to figure out what was differnt about the xbox, I went in and changed the output on the xbox and cycled through the different HD output settings. Turns out it makes the sound in every mode but 1080i. Could the issue be the same as stated below? Thank you for your time
The fix for this was so easy.
Turns out it was a Pharite(spelling?) that was vibrating. It was resting on top of one of the coils and was vibrating. The tech removed it and the problem went away.
Usually answered in minutes!