I love the way you think Brach. Great suggestion and I have some more findings.
With the power off, I metered from pin 24 of the IC to ground and swept the rate knob. I found the values ranged from 0 Ω to 3.28 KΩ (that’s not a typo… I attached a pic – it’s a little difficult to see the small K in the lower left of the screen but it’s there). I also metered directly on the center lug of the rate pot to ground and I’m getting the same range – 0 Ω to 3.28 KΩ.
I stopped troubleshooting there and didn’t bother removing the IC. I believe this tells us the circuit is solid from the pot to the IC and the pot is probably our culprit but I’d love to hear your analysis as you seem to have a great understanding of this circuit. Again… thank you so much.
