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A week ago Edited: A week ago, prashantakerkar
https://en.wikipedia.org/wiki/Color_television

Can this Defect happen in a Color Television Set?

Defect : No Colours. Only B & W colours seen similar to Black & White colour television.

What will be the Solution if the above Defect is visible?

Possible Solution : Replacing the RGB Cathode Ray Tube will solve the above problem?

Can RGB CRT be repaired?

Thanks & Regards,
Prashant S Akerkar
Post Merge: 2 weeks ago


Thanks.

https://en.wikipedia.org/wiki/Cathode-ray_tube

If the problem is with CRT Electron gun, Can this be repaired?

Thanks & Regards,
Prashant S Akerkar
Post Merge: 2 weeks ago


https://en.wikipedia.org/wiki/Electron_gun

Thanks & Regards,
Prashant S Akerkar
Post Merge: A week ago


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wrote...
Educator
A week ago
https://en.wikipedia.org/wiki/Color_television Can this Defect happen in a Color Television Set? Defect : No Colours. Only B & W colours seen similar to Black & White colour television. What will be the Solution if the above Defect is visible? Possible Solution : Replacing the RGB Cathode Ray Tube will solve the above problem? Can RGB CRT be repaired? Thanks & Regards, Prashant S Akerkar

Completely colorless, black and white displays of color broadcasts indicate a weak signal, defective chroma chip or chroma chip connections or a faulty color oscillator
Source 1) https://www.techwalla.com/articles/what-causes-color-problems-on-tvs
2) https://www.ebay.ie/itm/Vintage-RCA-CRT-3RP1-RCA-Cathode-Ray-Tube-Oscillator-NOS-NIB-BangyBang-Tubes/273469197908?hash=item3fac08ce54:g:zJsAAOSw0iBboHB1
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Staff Member
A week ago
Could be one of several issues. I found this online for the diagnosis of your issue:



First, confirm that the source is actually in color - try another channel or input device.

Next, check the settings of the color control - it may have accidentally been turned down. If your TV has some kind of automatic picture mode, try turning if off and adjusting the color control. Try adjusting fine tuning if you have such a control and the problem is with a broadcast or cable transmission.

At this point with a confirmed color signal source, there is a problem with the chroma circuitry.

Note that to the average person, the obvious question becomes: is my color picture tube bad? The answer is a definitive NO. It is virtually impossible for a defective CRT to cause a total loss of color. A defective CRT can cause a lack of a primary color - R, G, or, B or a short between two colors which will mess up the color but is not likely to result in a black and white picture.

Some possibilities in no particular order:

  • Weak signal or defect in tuner/IF causing loss of signal strength.
  • Color killer set too high (internal control) if it has one.
  • Defective part around the chroma chip/circuit. Faulty color oscillator.
  • Bad connections in area of chroma chip/circuit.
  • Defective chroma chip (don't suspect this first just because it is probably very expensive).

Try prodding the main board around the chroma chip with an insulated tool to see if you can make the color come and go.

I had one set where a $.02 resistor decided to open up causing just this problem - perfect BW picture, no color. Another had a coil with a broken wire.
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wrote...
A week ago Edited: A week ago, prashantakerkar
Thanks.

So In reality, the problem can arise in a LCD/LED Color Television Set where there are no Colors but only B & W colours visible similar to having the old Black & White television set.

So as you mention, the problem could be probably in Chroma integrated circuit defective.

Doing some research in general, Do you feel a electron gun in a Color Television Set can be repaired?

If not, why ?

Thanks & Regards,
Prashant S Akerkar
wrote...
Educator
A week ago
Doing some research in general, Do you feel a electron gun in a Color Television Set can be repaired?

They generally replace the entire gun assembly unless it's so rare it's unobtainable.

LED/LCD televisions don't have this problem.
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A week ago Edited: A week ago, prashantakerkar
Doing some research in general, Do you feel a electron gun in a Color Television Set can be repaired?
They generally replace the entire gun assembly unless it's so rare it's unobtainable. LED/LCD televisions don't have this problem.

As you mention, LCD / LED don't have this problem, What is/are the reasons ?





Thanks & Regards,
Prashant S Akerkar
Post Merge: 2 weeks ago


Thanks.

https://en.wikipedia.org/wiki/LCD_television
https://en.wikipedia.org/wiki/LED_display

As you mention, the above Problem has been eliminated in LCD & LED Color display which do not use the CRT.

If the problem of viewing B&W colours instead of all colours in CRT Color television set was seen sometimes, this problem will not come in LCD & LED Color screen at all?

If Yes, what are the reasons?. The Chroma integrated chip cannot get defective in LCD / LED Display ?

Thanks & Regards,
Prashant S Akerkar
Post Merge: A week ago


https://www.google.com/search?q=chroma+integrated+circuit&prmd=isvn&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiv6NjHqKnjAhW38HMBHXlKChYQ_AUoAXoECAsQAQ&biw=360&bih=592

Thanks & Regards,
Prashant S Akerkar
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A week ago
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In an LED display, each pixel emits 3 colors, I think red, yellow and blue—and then mix all the colors to form white light. So in an LED display, individual pixels die out, and if all of them get shorted, you need a new panel.
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A week ago Edited: A week ago, prashantakerkar
Thanks.

Vacuum Tube Radio Repair



Thanks & Regards,
Prashant S Akerkar
Post Merge: A week ago



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Educator
A week ago
Really cool 😎 thanks for sharing the video
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