Son of Screamer issue - Latchup?

[r080]

I built a Son of Screamer and have been having problems with it. It worked fine before boxing. Still fine once boxed up. Trying it out, I decided there was too much gain in the lower range of the knob and started experimenting with different diodes, opamps, and feedback resistors (though it is now at stock values). At some point, it stopped working, and had unexpected voltages. It seems to get stuck at the rails. Is this latchup? I have had the same result with a couple different 4558s and an OPA2134.

Board documentation:
https://www.delykpcb.com/product/casey-jones-son-pcb/?attachment_id=1056&download_file=5c5b8879b14e3

I used the values from AMZ with the exception of currently using BAT41s:
https://www.muzique.com/tech/scream.htm

The opamp voltages are below.

1: 1.4
2: 4.7
3: 4.7
4: 0.0
5: 8.9
6: 8.9
7: 8.9
8: 9.5

Measuring voltages today, I disconnected power, waited for a bit, then reconnected. Suddenly pin 2 went high as well.

With the chip out, pins 3, 4, and 9 were the same, as expected, and the others were floating or changing like a charging cap.

[anotherjim]

Those chip volts are so wrong it suggests a fried chip or it's in backwards!
Anyway, there's no way pin 5 should have anything different from pin1. If the amp chip is good, I would take it out and DMM test for continuity and short circuits using the schematic.

[ElectricDruid]

It's not latchup. If you've tried different chips and still get the same thing, it can't really be the chip - it must be on the board.

The fact that pin 1 is different from pins 2 and 3 is very definitely not right! Something must be dead or shorted around there. C4 dragging it to ground perhaps? ...but then, maybe not because pins 5,6, and 7 are all +V, which looks like something's pulling them up to the other rail!

Something's wrong somewhere, but I'd say you're looking for a dead component, broken trace, a bad joint, or a short. If you've been swapping parts in and out, it's pretty easy to break a track somewhere or leave a little blob of solder where it shouldn't be.

[r080]

It has taken a while to get to this. I measured the feedback path from the first opamp input to output, and it was open. The opamp wasn't failing, it was just open loop. I must have burned a trace while modding. It works now with a wire jumper across the open trace.