Has anyone ever turned the sound up high enough to blow the speakers? I once had some high end stereo speakers that suddenly developed a "rattle" and when I quizzed my teenage son, I found out that he had cranked up the volume in my absence and blew one of them. Cost me a ton to get it fixed.
I'm assuming the same could happen to the smaller speakers in a TV. Other than that, I have no idea. Hopefully someone else will be able to help.
Good luck.