Re: [help] Only noise being seen while IQ balance / phase lo / phase hi.
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Is IC10 pin 4 at 3.02 or is that a typo and it is pin 6 at 3.02?
On Thu., May 28, 2020, 11:50 a.m. Jose Tent, <ksaito2@...
So just to kind of gather my thoughts.......and summarize for the benefit of those trying to help me.
- 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.
Things Checked and thought to be validated:
Items found to be inconsistent with spec outlined in the manual: Few items that are way out of spec in RED. Input voltage is 12.36V.
- 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)
- 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.
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