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Old 07-20-2023, 01:55 PM
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Yamamaya42 Yamamaya42 is offline
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Location: Round Rock TX
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Quote:
Originally Posted by timmy View Post
I can’t see how the IF could be the culprit it’s been fine I still have a good b&w picture still it gradually got harder for the color to sync up now it’s gone
https://hackaday.com/2018/01/18/know...ideo-waveform/



It's exactly what happened with with my CTC-16XL, I had color with direct input video, but not from tuner, a messed up IF WILL BLOCK color, cause the timings getting to the color circuit will be distorted, in my case, the 4.5 mhz trap was WAY out of tune, blocking all color, leaving a perfect BW screen, the IF on mine is still not fully right, but works well enough.

But yes, a borked IF can distort the colorburst signal timing, leaving just a BW screen, this can be tested by once again removing the 3rd If, and putting in direct video at test point B , as you have done in the past, if you see no color, then it's the color circuits, if you do, then is a problem before the color circuits.
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