The level pot may be 100k, but that isn't the test that matters, what does is whether the wiper makes contact through its range.
IC1-8 feds directly to IC2-6. Op amp inputs are at "virtual ground" and you can't often read signals there, so what does the output of that amp look like at IC2-7?
Is this drawing from Boss? The switching circuits are missing.
IC1-3 is the control voltage pin - the IC is a VCA. What is going on ther? Does it vary with signal level?