|"Not sure what other info is needed"|
Model/model number of the TV would be helpful, system specs would be helpful too. I kinda doubt you're still running XP SP2 (or are you?). Does the TV make the noise all the time, regardless of whether it's connected to a computer, used as a TV, or has nothing connected to it at all? The noise is probably caused by a bad capacitor.
"TVs are not user serviceable"
Not true. If it's still under warranty, I wouldn't think of opening it up but if the warranty has expired & you've got the skills, all you'd have to do is open it up & see if you can spot a leaking or swollen capacitor. They're not all that difficult to change out if you're handy with a soldering iron. Another possibility is swapping out the entire circuit board. If it's a common problem with your model, the boards shouldn't be too hard to find.
message edited by riider