TV Screen Gone Green Red Yellow etc

Hello
If you see the picture in yellow colour, means that there is no blue colour output from the video drive section in your tv, Yello is the mixtrure colour of red and green. Green is actualy there. blue colour is absent.
To detect this fault, you must open your tv. Just look in to the video output section, can be located at the picture tube base card, which is plughed into it diretly. See for any loose soldering points there. Check whether transisotors are used for red, green and blue output stages, or an Ic or three seperate Ics are used for this purpose. Anyway, blue catode of your picture tube pin gets a hig voltage, and so the blue emission is absent. You just check the voltages at red,gree and blue catodes, at the respective picture tube pins, which can be taken at picture tube base card. All of these three pin voltages must be somewhat equal to each other. In your case, no voltage at blue cathode will be higher that the other two. Check for the reason. It may be due to an open video output transistor [blue], or an Ic, of one Ic if used for the three colour outputs. Check and replace the same, will rectify your problem. Ok
If you have andy difficulty, get it to me through Fixya. Ok
Gopakumar, India.

ok well "tube" tellys as they are called use an electro magnet to keep the picture stable and colours correct its called gaussing now if you have a speaker or something magnetic nearby it will stuff up the colors but only normally producing colors like purple,green, or white
if you have colors across the screen (that aren't caused by magnetic force) then you need to take it to a repairer or decide wether or not to buy a new one this issue can turn out to be quite hard to fix and can be expensive the different colored electron guns may be burning or burnt out causing pale color or it could be as simple as a power transistor in the H.V supply has shorted out..and causing power issues to the tube.
hope this helps,ben

I have a 21'' NEC TV Screen and it about 3 year old. the colour has gone to yellow and green color and the red etc

sounds like the blue tube is gone out

The picture tube of the tv has 3 color in CRT Red, Green, Blue. The red cathodeof tv set has no function, its either the resistor become higt resistance, that why u need a repairman to replace it.

if you set is over 4 yrs old the tube is at fault,you may try to adjust the screen settings.

i think you have weak picture tube. when gun becomes faulty this happens. Measure Red -Green-Bluue cathode voltages. and filament voltage.if everything is perfect then the problem with your picture tube assembly. Contact service centre for further rectification

Hi there my t.v has a similar problem, I turned it on and the colours arn't right, there the colours go out in three circles mainly mainly blue, green, red yellow, but depends whats showing on the t.v? Please help.

With the set being 12 years old, I'm sure the picture tube is near the end of its useful life. You probably have a defective semiconductor, either an IC or transistor that has gone up giving you no color, but with the green picture, it is not likely worth repair.

Hi, J ! You didn't say how old you set is, but to me it sounds like you may have a warped shadow mask in you picture tube. A shadow mask could be compared to a piece of screen wire. It's function is to make the electron "beams" from the three electron guns strike the proper phosphor dot to produce the proper color- red-green-or blue. If this is the case the picture tube would requie replacement. Stargazer