SOLVED - Sagan Delay - Troubleshooting Help Request

[Toy Sun]

OVERVIEW
Wow, this one has been so challenging. I changed dual PCB strategies halfway through the build, wrecked my delay board and both Daniel (Carcharias Effects) and Chris (DC6FX) helped me out and got me a replacement delay board.
Take 2 is wired up and it's a beast, compounded by the fact I didn't use board mounted pots - bad idea, but this will be a great layout... when I get it to work.

ISSUE/STATUS
Signal passes through circuit - input level control works and controls gain
All LEDs light up, bypass and LFO
All ICs show good voltages the VB or V+ pin (VB= 4.67V)
Tone controls don't seem to do anything.
No delay of audio signal passing through circuit
There is a faintly detectable sound coming from the delays - kind of a pulsing sound, varies with delay time setting. Mix control controls the level of this sound.

Seems to be that audio is not getting to the delays?

The challenge here is probing for voltages, as this physical connection between the two boards makes it really hard. That said, I could wire up a jumper and then do that, but was hoping that maybe the above specific symptoms might be a pretty good clue to the issue.

I've attached photos and schematics.

Thanks in advance for any help you might have.

John

[anotherjim]

You need an audio probe.
The first thing I would look at is to get audio on pin4 of the audio/delay connector. This should depend on whether the tails switch is on. The Tails function just kills the input signal going to the first delay IC5 leaving whatever audio is recirculating in the other 2 delays to decay.
If you can get signal to the delay board, the next check is for that signal to be on IC5 pin15. This is where it enters the chips delay line. You should then get signal out of the delay at pins 12 and 14 with some delay. If you don't, measure the DC voltage on pin5 and report back.

The background noise is probably from the modulation oscillator (LFO) based around IC6 and really only signifies that that part is working.

[Toy Sun]

Thanks Anotherjim,
Just needed that push to get probing. I realized that I had these Dupont wires and some other multipin stuff from Arduino and it was perfect for separating the two boards for troubleshooting. That said, it was all on the audio board and I only had to go in about 5 components before I found the issue. I used a 2N5457 that came from a little bag I had marked "check these, may be fake". Not sure if the transistor was bad, but I got into a jam with the socket so I desoldered it, replaced it and the transistor and now it works.
This project has been quite the learning experience - mostly about sockets. I've learned a hell of a lot about desoldering multipin sockets (also have had this with rotary switches... why me?). So I'm way better with using desoldering braid and also picked up some ChipQwik desoldering material (flux and very low temp solder). Pricey, but amazing stuff.
Anyway, the circuit is working and it's very cool. I'll do a full write up as another post.
Thanks again Anotherjim!