SOLVED No sound when effect off but LED and sound work when switched on

KdubATX

Member
Hello, this is my first build and for the most part all has been smooth but I’ve just finished the little green scream machine and successfully get the LED and effect when switched on but lose sound when switching off.
Using the power I/O module to make things simple and for the most part it was but I am doing a bit of unexpected troubleshooting.
Pics attached. I’m hoping it’s a small fix that will all be more apparent in the morning but figured I can share in the meantime.
Thoughts welcome.
 

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Im not a pro but it looks like you have a bunch of cold solder joints on your 3pdt and on the i/o too. reflow all those joints so the solder adheres to the component and the pad on the pcb.
 
Reflow your solder joints on the 3PDT. That’s where the on vs off signal switching is happening (and failing).

That said, your soldering needs work and I’d be surprised if you didn’t get other issues down the line. It always takes a while to learn how to solder effectively, so watch a video or two and practice on something if you can (and if you can’t , find something to practice soldering and even better desoldering).

The bubble solder joints are not effective connections for the parts. Also, looking at your component pads, you can’t really see any solder which has come through and formed a nice connection. Make sure you’re getting good contact from the soldering iron to both the component and pad, met the solder to the component and not the iron. Watch the solder melt and stick onto both parts. It takes practice but is essential. Trust a person with a drawer of shame..
 
Looking at the soldering on the switch PCB I am surprised that the effect works either. Resolder that and you should be fine. Just a tip is that those switches are easy to damage with too much heat. Make sure you have a nice hot iron so you can get in and out quickly, and take a break between each pin to let it cool. Bypass is usually a simple circuit - Input jack -> switch -> output jack. If the effect works, then you know the connections for the jack are working, so the switch pretty much must be the problem.
 
Right on thanks for the feedback I was trying to be quick and gentle on the switch so as not to use too much heat but will reflow everything after morning coffee. It’s been several years since I’ve done soldering work so no shock I’ve done a pretty rough job of it. Will post update a bit later cheers.
 
Hmm well cleaned up but same deal. I get overdrive and LED but nothing when effect switched off.
 

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Yea that’s just weird. Just for info this is how it works

1 4 7
2. 5. 8
3. 6. 9.

So the inout jack attached to 2 and the output jack attached a to 8. 3 and 9 are jumpered together. So your situation it sounds like when the switch is in the position that 2-1, 5-4, 8-7 are connected it is working. Guitar comes into 2 goes to 1 which takes it to the effect, the effect comes out enters 7 which is connected to 8 and sends the signal to the output jack.

In the other position 2-3, 5-6, 8-9 are linked 3-9 connected via a trace in the pcb. So your bypass signal goes from 2-3 then the trace takes it to 9 which is attached to 8 and then heads to the output jack.

As jimi said check your continuity between 2-3 and 8-9 in the position when the effect is bypassed. I’d also check your continuity between 3 and 9 as that should always be there. If there’s no continuity between 3 and 9 you can always just solder a wire between the two. I might also be concerned that you have a solder blob under the board causing 6 to make contact with 3 or 9 which could be causing it to ground out. Can check for continuity there as well.
 
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