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Old 11-24-2022, 08:41 AM
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timmy timmy is offline
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Join Date: Jan 2011
Location: Delaware ny
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Quote:
Originally Posted by Username1 View Post
Good Morning & Happy Tofu Turkey & Gluten Free Dinner Rolls Day to Everyone!

Timmy, I think for the first order of business, you should turn that detector diode around
& see if it makes a difference, It's just a signal diode, no 2 amps of current
running through it so you can't explode anything. If there ain't no improvement,
then just put it back....

Also back onto the look of the picture, I think you should also check the color killer
knob & with a so called picture on the tv, you should turn that control back & forth
& see what you get.... Turn the color knob up to about 1/3 & let it sit there....
You know what the color killer does, on a off channel with snow on the screen
a working color killer will make the snow B&W, Color Killer set wrong will
leave it with color snow.... It will also Not let the color circuits run on
B&W tv shows, so there might be odd color effects mixed in with a
picture that should be B&W. Your current Negative looking picture
looks to me like an open delay line, resulting in only color signal
being displayed on the screen, only here it's not color....
So with just turning the color killer knob lets see
if there is any effect there.... If no effect at all
then turn it fully counter clock wise & let it
sit there, so it's off, or set it to where it
was originally if you think no one ever
turned it and let it sit there....

Also I asked about the coils in that area, and you said that the IF Coils were already
checked, but that is not the coils I'm interested in....

I'm wondering about everything in the signal path of the Detector on-to the video
amp & output. L7 - L14, You don't have to take them out because they are all
low ohm, just test each series run of 3, you can see it amounts to about 6
ohms for each run of 3. Check R59 - L16, L17, R65, follow the signal
path through the delay line, (Check it too) & follow the signal path
to V5, are the voltages there close to what they should be? Does
the Brightness & Contrast knobs work properly? When you
have that negative looking picture on the screen,
does the Bright & Contrast have normal looking
effects on the screen?


.
As for the color killer pot it works and the negative picture get color snow on the edges when turned up and brightness works as it should and the contrast does make some difference with the video as it is. The detector diode when I first removed it and tried another I marked the cathode end and made sure I put it back right and tried another yesterday and made no difference. I know what you mean about color snow I had that in the beginning but no more and really don’t know why. I have snow noise in audio and minimal snow on screen but no color snow like it once had. I did inject video again at point B and gave it some color and that worked out good. I listed the video amp and output on a previous page. This is injected video at test point B and just a quick addition of color so would this rule out any problems with the resistors and coils and delay line.

Last edited by timmy; 04-24-2023 at 04:16 PM.
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