So just to kind of gather my thoughts.......and summarize for the benefit of those trying to help me. Symptom:
Things Checked and thought to be validated:
- No tone for IQ balance / phase lo / phase hi even with volume pot turned to the right.
- value at IQ balance / phase lo / phase hi is zero with graph jumping up/down randomly. (Assumed to be just noise)
- While doing BPF adjustment, the volume of the tone goes up suddenly from near zero to almost 100% in a very small range around the middle.
Items found to be inconsistent with spec outlined in the manual:
- All torroids and its continuity. (T1 has been checked at least 5 times thoroughly now)
- Proper install of Volume pot. (value slides smoothly from 5k to zero as measured on the board)
Few items that are way out of spec in RED
. Input voltage is 12.36V.
- IC6 Pin #3,5 measures around 2.5v [manual = 1.5ish v) *within tolerance ??*
- IC7 Pin #3,5 measures around 2.5v [Manual = 2v] *within tolerance ??*
- IC8 Pin #5 measures around 2.37v [Manual = 0.67v]
- IC9 Pin #3,5 measures around 2.5v [Manual = 0.65v]
- IC10 Pin #1,2,3,7 measures 12 volts [Manual = 5.83v] ??!!??!!
- IC10 Pin #4,5 is measuring 3.02 and 2.31v [manual = 4.21 and 3.94 ] *within tolerance ??*
The excessive voltage in IC8, 9, 10 shows issues. Just not sure how that is happening. Continuing to troubleshoot.