debugging Neutron ... pressing with my thumb helps?

[half_smith]

What's the go-to prognosis when touching part of the board (underside) with my thumb seems to help?

I've checked joints and continuity along traces... am I an inductor?

[jimilee]

I believe we call that stabbing in the dark.  Reflow all your solder joints, check your voltages, then use an audio probe.

[half_smith]

haha, definitely stabbing in the dark.

I've done as you say, found a bad joint, and replaced the charge pump, but something is weird in that one spot of the board.

It's right where there's an "optional" bipolar power input (i'm not using, although I've started thinking I might, because I hate charge pumps!),
It's like an inductance thing or some kind of grounding..

am I grounding it by touching?
Does my thumb make an electrical bridge between joints?

[half_smith]

Hey gang, just an update.

I have the Mutron/Neutron working... but I've been dealing with an incessant whine/squeel

I've jumpered pins 1,8 on the MAX1044, helped a lot, but still have whine all over the place.

Turns out, I missed a small detail in the build doc, about using 2 "CHOKES" when going single +9v supply - as I am doing.

This means I was maybe intuitively correct about my thumb helping via some kind of induction. I was pressing on the areas where the Chokes are meant to go - I will install them next week when they arrive, but I have reason to believe this is the solution.