Originally Posted by GolgothaAvante
I can't test with headphones - it's a television, and it's also precariously high in a ladderless house.
The screech is just a sudden increase in volume. It's almost like whatever we're watching just gets incredibly brain destroyingly loud all of the sudden, but only for about a second. The speakers are built in to the TV, and I'm only able to replicate the problem if the PS3 is in 480p mode. This only occurs in 1080i.
First, remember I can only go by what you write since I can't hear what you are hearing. So, please try to be as accurate as possible.
You said a screeching sound but also said it sounds like what you are watching got very loud. When this screeching sound occurs, can you still hear the words/music or is it just electronic noise? How long does this sound last?
The reason I'm asking is that at first I thought this might have been interference. However, if the words/music are still inteligible but have just gotten very very loud, then that is a completely different problem. Interference over HDMI will not raise or lower volume levels. Digital distortion will sound like hissing or a loud ping or a few other electronic-type sounds but not greater or lower volume levels.
Also you said this only occurs if the PS3 is in 480i but then you added "This only occurs in 1080i". I don't know what you mean with the 1080i comment. Could you please explain further? Also are you gaming when this occurs or watching a movie or streaming video? Or does it happen with any type of input?
At one point I was thinking someone in the neighborhood had a CB radio that was bleeding into your speakers and that would sound like a large screech. But if what you are really saying is that the volume gets very high for a second or two, that sounds like a TV audio board issue.
As Joe said, eliminating the PS3 as a possibility would help pin down the problem further.
BTW, to test with headphones you would simply use a y-cable that had two RCA plugs on one side and one 1/8" stereo socket on the other. Radio Stack used to sell tons of these. These will even work with TVs that have analog stereo outputs in the back.