Hi Paul,
I looked the center bias/regulator board over until I was blue in the face. After checking the component position, orientation, and connection to and from the board multiple times over two days, I was still experiencing bias voltage issues. The T20 and T30 could be adjust to 145v with the other terminal at ~100V.
Although I did this numerous times, I rechecked continuity for all ground connection. Although the ground terminal T8 looked good and measure continuity before, it seemed to be spotty today.
I check continuity between T4 and T7. Nothing. T10 and T7 nothing.
Although I had good continuity between T7 & T6 and T7 & T21.
Touched up terminals T4, T8, and T10. Now I had good continuity checks between T7 and all ground points.
Powered back up and T20 and T30 were both measuring ~165v - ~170v. Turned potentiometer on the B-side of the bias/regulator board for T20 and adjusted to 145v. Moving over to T30 and adjusted the potentiometer on the A-side of the bias/regulator board to 145v. Re-measured both T20 and T30 and they stayed at 145v.
In conclusion a bad ground between T4, T8, and T10 caused my biasing issue.
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High-Five to you and thank you.