1971 GE Portacolor H3 chassis color help

[zeno]

Try this it will eliminate the tuner.
Put signal on & tune the fine tune until the pix gets wormy.
You should still have color. Watch it over time for drift.
Almost sounds like you have 2 problems.
BTW these rear controls get tin wiskers. Shango did a Utube on it.

73 Zeno
LFOD !