RGB on a tv question

[njtermite]

I have a tv were the RGB (the colors) is messed up. Every thing looks basically black white and green. I was wondering if anyone new if it was a resister or is it the tube? And any suggestion on how to fix it?

Thanks,
Mark

[Al_The_Man]

You did not say what make/model etc?? There is a multitude of things that can cause missing color problems. I suggest you try one of the electronic repair N.Gps. e.g. sci.electronics.repair.
Al

[njtermite]

Thanks for the reply,

The make is: Magnavox
Model number: CS54742 A401
Chassis number: 27Y100-00AA

I will also check out those news groups.

Thanks,
Mark

[teilhardo]

Do you have a magnet anywhere near it? Sometimes that distorts the EM field

[ynneb]

I have a monitor that you must keep pushing the connector on the back of the tube on. It has odd colours if you dont push it back.

Did you know the voltages on the back of a picture tube were very dangerous. Even when the TV is turned off there can be residual voltages.

The way you phrased you question "I was wondering if anyone new if it was a resister or is it the tube?" make me think you shouldnt be messing with it anyway. Sorry If I am wrong. Just been precautious.

100 bucks for a repair is better than getting a serious shock.

[njtermite]

Teilhardo, nope no magnet near it.

Ynneb, yes I’m highly aware that there is high voltage in the tube. I remember watching my dad work on TVs and ground the tube. If it’s something to do with the tube then I wont touch it. Thanks for giving the heads up on that though. I was thinking if it was just a resister or something I could just fix it myself, since I have worked with circuit boards before.

Thanks,
Mark

[Al_The_Man]

To diagnose CRT or biasing defects affecting color, start by tuning in a B&W picture or turning the colour all the way down.
Does the screen have blotches of colour? If so it may be the degaussing circuit or need manually degaussing.
In B&W, does the screen have an overall tinge of red, blue or green? If so does the colour change when moving the brightness from max to min? If so it may be CRT problem.
If the screen stays B&W from min. brighteness to max, then it may just be a crt drive setup using the three crt drive controls usually labelled Screen, Drive or Control, they are often pots coloured red,green & blue. These should be adjusted with the brightness and contrast at medium for a B&W picture.
If you cannot achieve a black & white screen (greyscale) i.e if one colour appears to be weak or missing then it points to CRT emission or crt bias, due to a R,G, or B drive transistor.
If very closeup on a B&W picture, the outlines (top, bottom or sides) in some parts of the picture show separate red,green,blue dots, this points to requiring a convergence set up.
If you intend doing any meaning maintenance on your own set, I recomend getting a service manual.
Al