Zombie Choir II x2 same issue

[Kroars]

Been a while since I’ve been absolutely stumped and figured I’d post in hopes of some help. Granted, this is a PCBMania board (go figure, the first in awhile to be an issue…. Maybe karma for straying..)

So, followed build docs to a T building 2 of these. All components tested prior to installation (aside from IC’s, although they’re from Mouser and Cabintech). Also, tried a few MN3207’s as well as V3207’s same issue.

What’s the issue? No effect whatsoever when either of the two pedals are engaged. I get a completely dry signal, knobs and toggles have no effect on the signal at all. The only thing that happens with the controls is when you change the on-on toggle (for vibrato/chorus) it kills signal 100%. No sound.

I’ve been reading a bit about the circuit and it does seem to be prone for issues. I was hoping someone else may have built this with some success.

I’ll add, there are a couple wires (NOT JUMPERS!! As per build docs) to be connected to their respective solder points on the pcb depending on whether you use the MN3007 or MN3207. I’m not sure what the builds docs mean when they say “add a wire (not a jumper)” to me they are the same thing. Hopefully that’s not where I messed up as they’re on the under side of the pcb.

I the two boards I have are both the first version. Here are the build docs I used:

https://pcbguitarmania.com/wp-content/uploads/2020/02/Zombie-Choir-1.1v-Building-Docs.pdf

Thank you for any help you can provide!

 

[Fingolfen]

I've only built one of the Zombie Choirs, it works, but it ticks...

 

[Kroars]

I've only built one of the Zombie Choirs, it works, but it ticks...

Do you remember if it had trimpots on the pcb? I wonder if the 1st version is a little screwy. Looks like they had versions 2,3 & 4 within a couple months of each other. Maybe it went out faulty. Can’t say I have a ton of trust in PCBMania.

 

[Fingolfen]

I'd have to double check, it's been ages...

 

[PJS]

To me, if the build docs are specifying a wire not a jumper then I would be using insulated hook up wire, not uninsulated connectors (e.g resistor legs). If that is what they mean then they probably should have specified insulated wire, but that is what I would be doing

 

[Diynot]

Just checked the pcbmania Facebook page and there is one post from 11/2021 with the same problem, but no resolution. they were mainly focusing on the 4046, but it looks like you have the “appropriate” version.

 

[Kroars]

Yeah, this is a head scratcher for sure. May just be a defunct design. As I mentioned, there seems to be a handful of “versions” in a very short period of time. I certainly appreciate the help everyone

Oh and for clarification, I used insulated wire for the couple connections.

I’ll also add that out of hundreds of pcbs I’ve built, mostly PedalPCB, but a handful of Effectslayouts, DEFX and PCBMania; the latter mentioned I’ve had the least amount of successful builds.

 

[Diynot]

They’re low tier trash for sure. They have just enough working boards and unique (don’t read original) circuits to keep people rolling the dice.
Have you tried tracing the board as compared to an original/non pcbmania schematic? I know a lot of issues with their boards comes down to missing connections/links

 

[Kroars]

They’re low tier trash for sure. They have just enough working boards and unique (don’t read original) circuits to keep people rolling the dice.
Have you tried tracing the board as compared to an original/non pcbmania schematic? I know a lot of issues with their boards comes down to missing connections/links

I may just breadboard the circuit, it small enough. Hopefully learn more about that particular circuit while doing so. With any luck, I’ll be able to compare that to the ZCII from pcbmania. Thanks again, my friend!

 

[Kroars]

In case anyone else has the 1v0 pcb of the Zombie Choir II from PCBMania, I figured I’d update the thread. I ended up getting a couple MN3007’s (this pcb says you can use either the 3207 or 3007 with a couple different jumpers, IC dependent), moved the wire jumpers from AG and B8V to A9V and BG to accommodate the MN3007 -and wouldn’t you know it, the build works as it should. It looks to me like this version of the pcb doesn’t work with the V3207 (probably due to the jumpers and incorrect traces, but I’m open to suggestion) but it does work with the MN3007. Hope this helps someone. That’s what I get for straying from PedalPCB…..