My sony tv KV-19BMR1 color is my problem more blue?
Advance of any one colour, Red-Green or Blue, will be due to the some fault in the video output section in your Sony TV. When the related colour cathode of the picture tube gest improper voltages, say low voltage than normal it should get, then occures this problem. As you know, all colour TVs have three electron guns, otherwise called as cathodes, are there inside the neck of the picture tube. One emits blue, an other emits green and an other emits red. You are seeing the combinations of these three colours displayed in different ratios in your picture tube when a picture is being viewed. Keep this in mind and follow please.
All the above said three cathodes of the picture tube has some voltages applied to it to emit predetermined quantity of electrons from them, which determines the intensity of that colour. Now your TV displays blue in excess means, the blue cathode of the picture tube in your tv has a low voltage with respect to the other two have. Cathodes are negatively biased, that is as its voltage goes low it will emit more and more electrons, which will cause an abnormal excess colour of that cathode.
You just open your TVs back cover, without damaging any other components inside, after unplughint it from power wall socket. As you open the back cover, you will be first exposed to a small rectangular board, plunged into the neck of the picture tube, known as base card. It is pluged into it with the help of a socket, we call it as picture tube base socket, and it can be pluge out from it by applying a gentle pull backwards. Never make a right or left shake when you do this as it may damage the picture tubes pins or even break it.
Give power to the TV and keep switched it on and see the screen. Keep the colour control to zero position, and brightness to at about 30%, and contrast to 50%. At this condition, you shuld get a clear blacke and white picture. In your case now, you only get a picture with a blue shade. Locate the "blue cutoff control' if any fitted on the base card, [as latest sets have not], and it will be marked as "b-cut" usually. If it is there, with help of a plastic screw driver rate it just a little counter clokwise or clockwise, while observeing the picture, whethere it gets any change in colour or not. If there is no colour change, the colour output transistor related to blue cathode should me changed. It may be leaky.
If there is no color cut-off control is seen, you won't have this option. If so check the voltages of the three above said cathodes, and it can be taken with a multimeter set to 400VDC or above. it should be almost equal th each other, except a voltage difference of 3 to 4vDC is allowable. In your case the blue voltage will be more less than thi tolerence. You can take this voltage by touching the meter probe to pin number "3"_blue, pin number "4'_green and pin number "6"_red. Usually sont tubes have this kind of pin cofugurations. If the blue cathode voltage is seen abnormal with respect to the other two, replace video output transistor related to it. Thsi transistor also can be located in the base card describe earlier. Ok
If you have any doubts and difficulty, inform to Fixya, and they will gvie me alerts.
Keep every precations before opening the back cover. Keep children away from you and never allow them even stand beside you. Let an adult to be beside you while you do this work. Keep the TV pluged out from the wall power socket every time before you touch any of its inside components.
Be confident and patience. If you have some knowledge in electronics, you can do it by yoursef. If not, go for an experienced service personal. I thinks tha you yoursef will do and you can. Ok
Oct 22, 2010 |
Sony Standard (CRT) Televisions