I'm not sure if this is a universal thing with TVs. Whenever my TV (Proscan rear projection) is turned on, it lets out a constant high-frequency noise. With movies it's not a big deal, because it's more than drowned out by the HT, but with regular TV watching it's kind of a pain.

Is this a ground loop, or should I summon the repair tech yet again?

Does this happen even with the TV muted?

Maybe you are one of those unlucky folks who are very sensitive to the ~15kHz noise often generated by the high-voltage anode transformer supplying the CRT. Go to the local Best Buy and see if you "hear" the similar noise from other tube TVs and CRT-based RPTVs.

I've had monitors that do this. They generally last quite some time, but are really annoying. Of course, I don't know if this is the same issue or not (is your RPTV CRT based?), but you might want to call the repair tech after checking out other TVs like Sushi suggested.

Yes...actually the TV is muted most of the time (the HT setup takes care of sound). Have you experienced this?

I just talked to one of the guys in my office who services monitors. It's probably the main deflector board in one of your CRTs.

Had the same experience with a Sony 28" tube TV. The pitch of the "squeal" was intolerable. It was still under warranty so they sent out a tech. When he opened it up, he showed me a "coil" that looked like a compressed spring. He had an insulated screw driver that he used to touch it. The squeal would completely stop when the coil was touched. He shut the TV off, loaded the coil with silicone and told me not to run the tv for 8 to 10 hours. (To let the silicone cure) The set hasn't made a peep since.

actually i hear this high pitched noise pretty much with every tv I've ever been around, even when other people claim they cant hear anything.

I think some people just have sensitive ears to these frequencies.

Thanks for the tip. I'll give the techs a call.