[sdiy] another Jupiter 6 question

[Eric Frampton]

Hi y'all -

I'm working on the same unit that had the "all oscs 2 dead" problem (thanks again!), and have now discovered that the modulation button on the bender board isn't working. The button itself is making/breaking the circuits, but there's no effect happening. The LFO is working (I'm seeing a happy blinky light) and the bender is working correctly to both oscs. and the VCF. I think the problem is somewhere between IC4 and TR2, but I'm not sure. Here's what I'm seeing:

IC4 (IR9022):
pin 1 = 0.011V, making the switch changes it to 0.010V
pin 2 shows the same change as pin 1
pin 3 = 0.003V
pin 4 = -15V
pin 5 = 0.003V
pin 6 = 0.014V, making the connection changes it to 0.013V
pin 7 = 0.010V
pin 8 = +15V

TR2 (2SC2021, assuming I'm calling the pins correctly):
E = 0.011V, making the connection changes to 0.010V
B = shows same change as E
C = 0.626V, making the switch drops it to ~0.55V and the voltage keeps dropping over time from there as long as I hold the button down.

Thoughts?

Eric