No pedal signal for some of my first builds

mattly

New member
I’m building my second and third pedals now, having successfully completed a the “Death Cap” Doom Bloom clone, and I’m having trouble with not getting signal through either board. I’ve had a lot of problems with 3PDT wiring and for the sake of troubleshooting am running straight to the board and out on both of these, and am connecting the ground pad to the SW pad.

I’m new at this and perhaps should have tried some verroboard builds first, or perhaps something simpler. I’ve soldered switches onto mechanical keyboards before, but nothing this involved. And I tend to learn best by biting off way more than I can really deal with and then powering through it. I’ve done continuity checking on both of these boards and signal flows as it should, and haven’t found any ground shorts. I need to clean the board a bit with some isopropyl alcohol, but the soldering looks like it should be fine. I’ve heard about “cold solder” joints and am not sure how to recognize or test for these. I got a DMM for doing these projects and am still learning how to use it, I’ve figured out how to test continuity and voltage, but not how to test resistors. I’ve double-checked that I’ve got the ins and outs going to the right jacks, and have been using alligator clips to connect the wires to the jacks. Both boards will bypass if I connect the in/out pads. I recognize that since I didn’t socket the ICs that I may have overheated them, but don’t know how to test that.

The first is a Calamity Fuzz, which I started before I realized the pots/switches should go on the back of the board:

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The pad for the in jack burnt off, so I connected the wire directly to R1, which the schematic shows is junctioned with C1. There’s continuity from the end of the wire to C1. I recognize that with the pots on the wrong side of the board, full volume will be at anti-clockwise, and have been testing with the pot about halfway.

The second board is a Chalumeau and I soldered the pots on already because I couldn’t get them to sit in there and connect properly:

DAB4560B-6EEF-4270-8897-7A76BA860522.jpeg E3FA93B3-D5A7-4FF5-B220-533A1A4D5EC1.jpeg E2F4E863-884E-476C-812E-479279967FC1.jpeg 96848AF1-A35F-4ABD-96DE-B15F241E3141.jpeg

I’ve tried a couple of different LEDs for the vactrol but only a green one will light up showing it’s receiving signal. The wire for the SW pad had just snapped off but the “On” LED will light if I connect SW and Ground. I had a harder time testing continuity on this one because the PCB I received has a different layout than what’s shown in the build documentation.

I’m not really sure how to troubleshoot next, I was thinking of following the audio signal through each circuit and seeing what happens if I connect any particular point to “Out” to see where things might stop working, but would love some more seasoned advice.
 
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Your protection diode (d100) on the Chalumeau is backwards. That would make it not work. I'm concerned about the quality of many of your solder joints. It looks like iron temperature and/or solder type could be off. Also the corners of your pcbs have the solder mask scraped off. That could be causing issues as well. If you are using some sort of clamp for the pcbs you'll want to protect the surface from marring.
 
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What solder type should I be using? This is labelled 0.6mm “Sn-0.3Ag-0.7Cu”, and I have my iron set to 430C, I found it has a hard time melting it below that temp. But I’ve been using a pointy (“B-Series” ?) tip, I’m reading through the “Basic Workflow Tips” pinned in the other forum, it sounds like maybe I want to use a chisel tip instead as having more surface area means I can use a lower temperature.

I’ve acquired some covers for the clamps I’ve been using to hold the PCBs, aside from cleaning is the scraping on the solder mask anything to be worried about if I can’t detect any shorts?

I’ll try reversing that diode now.
 
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