HDTV picture jitter

[drbill28]

My brother in law has an HDTV. It's not very old. But he has a kid who has whacked the screen a couple of times. No damage. But what he tells me is happening is that the picture jitters up and down very rapidly. It's a very tiny amount but it's there. There is also a slight ghosting effect too. It's very bright. Mostly noticable on sharp edges and character like the programming guide. It happens on all the inputs and devices. DVD, PS2, Sat, VCR, etc. I don't have the model number, but it's an Hitachi. I'll ask him tomorrow what to check. None of the settings will fix it and neither will the "Magic Focus" feature. Any ideas what this is? I can't find anything on it.

 

[Kevinw]

Possible convergence board failure. Should be under warranty yet.

 

[drbill28]

I went over to their house and checked it myself. The picture is fine on the right side of the screen but from the center over there is the ghosting. Kinda almost like a severe focusing problem. When you're watching video you can't really notice it. But the jitter appears and is only noticable when looking at say the DVD menu, on-screen guide, or some other still image. Kinda shakes a slight amout very very rapidly. They don't know if it's still under warranty. Oh and the model is a Hitachi 51S500.

 

[drbill28]

I was able to fix most of the convergence problems for them. I found a guide to adjust it on their model. I did it fairly fast so it wasn't 100% perfect. But the picture is watchable again. It's only ever so slightly off. But I still see the shaking picture thing. Also I think the screen in the lower right might be slightly warped. The tickers on the news channels warp slightly as they leave the screen. Also the lines on the grid aren't perfectly stright in that area. But they say it's always been like that.

Thanks Kevin, I read what you said I thought to look for that.

 

[Kevinw]

Your Welcome Drbill28,
I have the reoccuring shaking with mine when the convergence and geometry is to far out of wack. Another thing to check is ovescan. Too much overscan has tickers and logos cut but too little overscan puts undue stress on the TV as well.

 

[drbill28]

Well, I assumed that the shaking might go down when I adjusted it. But it didn't. Things are pretty close in order in terms of convergence. There's definitely not too much overscan. I think it's just the physical screen. If I recall it's always had that little distortion that causes the tickers and the sort to look like that. going on since they got it. They do keep next to a window. Not facing the window but angled at about 45 degrees. But it wasn't always in that location. They're happy with the way it is now. Sometime soon I'll take my time with the convergence. The shaking could well be their satellite receiver, they don't have any other sources to try besides their DVD player but it's hard to judge it. The receiver is a model that tends to have problems.

 

[Kevinw]

Convergence/ geometry stress shaking happens all inputs.