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Panasonic CT-27L8G - picture alignment

Posted: Thu Sep 30, 2010 9:29 pm
by The Robman
I don't how well you can see this in the photo below, but the picture on my Panasonic CT-27L8G seems to be a little bit more compressed on the left side than it is on the right side. You only notice this when you have a channel guide or program guide on the screen.

Is there any way to tweak the picture?

Image

Thanks.

Posted: Thu Sep 30, 2010 9:36 pm
by vickyg2003
What is the electronic gizmo sitting next to the TV on the left? Is it a speaker? It might be as simple as moving that away from the TV.

Posted: Thu Sep 30, 2010 10:25 pm
by The Robman
Nah, that's just a thermometer. The picture was the same when the set was in another location.

Posted: Fri Oct 01, 2010 5:48 am
by vickyg2003
Well you've exhausted my knowledge. I had shrinking on one side of my TV that was caused by having the TV too close the the telephone.

Posted: Fri Oct 01, 2010 6:52 am
by zaphod7501
Usually there is nothing that you can do about that type of geometric distortion. It was an even bigger problem with the flat faced picture tubes they used in the early 2000's. It is a function of transformer windings. (horizontal output, yoke, pin amp)

Sometimes the power supply on really old sets can aggravate the issue but I don't know of any realistic fix. (power supply not "stiff" enough)

Posted: Fri Oct 01, 2010 11:05 am
by The Robman
Thanks Steve

Posted: Thu Oct 07, 2010 2:09 am
by digital_silence
The chassis # for this model is NA10.

I am not familiar with this set, but for most TV sets, the trapezoidal distortion (which looks like what you have, by your description (I can not determine that from the picture)) can be adjusted out via service menu. To enter the Service Menu, usually you have to press the unique button sequence on the Remote Ctrl.

As I said, I've never dealt with this model, but very often the Service Manual tells you how to enter the Serv.Menu.

I don't have a Service Manual for this set either (maybe Steve can help).

Quick google search brought the web site where you can buy it

Not sure if you want to go for all this trouble for the small bareable picture shrink though.

Posted: Thu Oct 07, 2010 6:48 am
by zaphod7501
Most pincushion adjustments are intended for the sides of the picture, not the top and bottom. (even though they may affect both) The height adjustments are generally done by pressing wedges under the yoke or sticking small magnets on the tube bell, but most of those corrections affect the entire width of the screen. (a scanning robot does the factory adjustments)

You can take a horizontal signal and use it to modify vertical output or a vertical component and modify horizontal, but not both simultaneously due to interaction. Pincushion uses a vertical signal to alter horizontal width on a line-by-line basis.

This distortion was never very visible on slightly rounded picture tubes because the overscan hid it. The flat, square tube faces presented new problems that were never solved because they were discontinued before they were fully developed.