[old_tv_nut]

Does the color oscillator alignment have you ground the phase detector output to adjust zero beat? If so, what happens when you remove the ground? Is the oscillator unaffected, or does the frequency change?

Try putting a voltmeter on the control tube input and see what happens to the control voltage as you ground/unground the detector. See what happens to the detector output/control tube input when the detector is not grounded and you adjust the oscillator frequency very slightly off zero beat. Trace back to the phase detector and back further to see where you are losing either burst or oscillator input to the detector.