faulty 3pdt - did I cook it?

[erm]

Bought a kit, and some parts for a few pedals a year back. Finally got time to build the first one.

Tested it - there's signal in bypass, but not when engaged. I traced the signal through the circuit and the signal is lost between lugs in the 3pdt. Between the upper right, and middle right lug in this picture: https://www.pedalpcb.com/wp-content/uploads/2017/11/3PDT.jpg

A DMM finds no continuity between these lugs when engaged. The other two pairs are ok. (and the other 3 pairs when bypassed).

So I guess the 3pdt is faulty? Is this likely to have been caused by overheating during soldering, or some other rookie error, or is it more likely to have been a faulty switch to begin with?

Not too fussed either way, has been a good opportunity for me to learn how to troubleshoot. I've also got some spares, so I can swap this one out.

Cheers!

 

[HamishR]

Sounds like you may have. It's not hard to leave the heat on the pin for too long and cook it. Soldering these switches is not difficult but needs a clean soldering iron tip, a shiny, tinned wire and not too much solder. You should only need to apply heat for a second or so.

 

[Erik S]

Bought a kit, and some parts for a few pedals a year back. Finally got time to build the first one.

Tested it - there's signal in bypass, but not when engaged. I traced the signal through the circuit and the signal is lost between lugs in the 3pdt. Between the upper right, and middle right lug in this picture: https://www.pedalpcb.com/wp-content/uploads/2017/11/3PDT.jpg

A DMM finds no continuity between these lugs when engaged. The other two pairs are ok. (and the other 3 pairs when bypassed).

So I guess the 3pdt is faulty? Is this likely to have been caused by overheating during soldering, or some other rookie error, or is it more likely to have been a faulty switch to begin with?

Not too fussed either way, has been a good opportunity for me to learn how to troubleshoot. I've also got some spares, so I can swap this one out.

Cheers!

You didn’t install the board upside down did you?

 

[jwin615]

Sounds like it warped/melted.
I'll add, as tempting as it is (subconsciously), don't flip/press a switch immediately after soldering the last leg. Like shutting a door after I stalling a doorknob... Some form of instant gratification made me do it.
I did that a few years back in the wee hours of the morning. Immediately questioning my entire reason, I tested it and sure enough that last pole was borked, even with pausing and alternating legs, it was soft enough to be warped.
I now not only don't do that but take care that the switch isn't partially depressed or accidentally depressed

 

[erm]

I swapped it out for another 3dpt and it's fine now. This time round, I waited for a bit longer between soldering the lugs, and tried to alternate the order around a bit, so I wasn't putting all the heat in one place.

I'm using quite fine solder 0.5mm. It takes a couple of seconds to feed in enough to fill in between the lugs. I might need to get some thicker stuff for switches and pots.

 

[Locrian99]

I murdered a few switches early on.

 

[Chuck D. Bones]

Pix?

 

[jwin615]

Pix?

 

[erm]

Bit shy about posting pix. Def a bit wonky in places. Feel free to school me. I'm here to learn.

The misfeatures I know off:

No LED, because I was impatient and couldn't decide how I was going to jam it in there. I'll save that for another day.

No heatshrink on the jack lugs because I don't have any yet.

Burnt the red DC jack wire. I now have jacks which I can mount from the inside, rather than in situ soldering, and silicon wire which shouldn't burn.

Def not OCD alignment compliant.

 

[Chuck D. Bones]

Looks pretty good. You may have noticed that the slots for the switch pins are much larger than the switch pins themselves. Your switch has PC pins and the switch board slots are sized for solder lugs. No problem, just keep in mind that it is not necessary to fill the holes with solder. In the time it takes to fill one hole with solder, you may well have overheated that pin. Filling each hole 1/4 of the way around is enough. Also, pause between soldering each pin. Give the switch body time to cool down.

As long as the jack lugs have enough clearance that they're not touching the housing, you don't need heat shrink. You can bend the lugs up a little to gain more clearance.

When you decide to install an LED, I recommend that you get an LED retainer that will hold the LED securely in place and connect the LED to the board using flex stranded wire. Put heat shrink over the solder joints on the LED to prevent shorts. You can get the holders on Amazon or eBay.