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I was able to determine that the AGC was taking out the tuner and the IF stages. Still no clue as to why, I used a fixed voltage supply for troubleshooting the AGC and when I was finished, the AGC started working normally. Weird...
Either way, I now have a decent black and white colorbar, but cannot get the color to lock. I ended up changing the 3.58 ECO transformer as it was seized and I was unable to perform the Color AFC Alignment. After performing that alignment, still nothing. I can get the color sync to a dead stop on the screen, but no lock.
The oscillator is running and gives a clean sine wave. The two things I did notice:
1: The input to the burst amplifier is not as clean as pictured on the SAMS. My input looks more like the plate of the color killer (though still ~50v) A lot of noise near the floor, though still the same shape overall.
2: The burst pattern is only 10v p-p versus the 30v that the SAMS calls for. I tried swapping the burst amplifier and chroma phase detector for known working tubes with no change. The burst amplifier voltages are all within the spec.
Thoughts?
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