SOLVED Need to remove 3PDT footswitch from breakout board (or bypass board entirely)

[DAJE]

I don't like footswitch breakout boards and don't use them, because if something goes wrong with the footswitch, you're screwed. Like now.

I'm using them now because I bought a couple of Aion boards and they're built in, I can't just use the footswitch because there's some other circuitry on the board too. Specifically, it's an Aion Deimos, a Tonebender M2, which I like because it has internal trimpots for dialing in the transistors.

I have successfully built one for myself, but this one is for a friend, and I was in a rush to finish it last night and I'm pretty sure I killed the 3PDT with too much heat. I'm in the southern hemisphere, it's summer, and I was surprised by how hot the switch was after I finished it. And... pedal no work. It works in bypass. LED works. It passes signal when it's on, but very quietly, and not at all fuzzy. Checking continuity, everything is connected to the ground. Including everything that isn't meant to be connected to ground. So that's no good.

Anyway, pretty certain it's the footswitch, specifically the right 3 lugs, which are all connected at the same time when the pedal is on. I compared that to my working pedal and that's not what the good one does.

Getting to the point: how screwed am I? I can try desoldering the switch from the breakout board but that's not easy - I've tried it before and failed. I'm more practiced at sucking solder now but I still don't feel confident that I can get the switch off without destroying the board.

My other option is to try to figure out how to wire the main board directly to a new switch and incorporate the LED wiring (do-able) and the extra diode and capacitor (maybe). Bypass the breakout board entirely. I think I might be able to figure out how to do that, but if anyone wants to draw me a diagram that'd be very helpful indeed. I think this is actually a better option, but it may be beyond me.

 

[princeofyams]

I've got a 'risky' idea for you...

So, first I'd cut the breakout board off the main board just for safties sake. Now it's a risk, you'd have to be careful... but if you have a dremel with a grinder head on it, cut 3PDT switch underneath the bottom (hopefully there's space) on the button side. If you can get the 8 around the outside than you can desolder and push the whole thing off from the middle pin.

I know, kind of a bush wacker solution, but not much to loose. You could probably just breadboard that breakout board anyway (worst case scenario).

 

[DAJE]

I've got a 'risky' idea for you...

So, first I'd cut the breakout board off the main board just for safties sake. Now it's a risk, you'd have to be careful... but if you have a dremel with a grinder head on it, cut 3PDT switch underneath the bottom (hopefully there's space) on the button side. If you can get the 8 around the outside than you can desolder and push the whole thing off from the middle pin.

I know, kind of a bush wacker solution, but not much to loose. You could probably just breadboard that breakout board anyway (worst case scenario).

Don't have a Dremel or a breadboard. Nice idea, though.

I do have plenty of unused footswitches, LEDs, and resistors, and I'm pretty sure I have spares of the diode and C11. I'm working on trying to grasp what needs to be connected where and I think I can do it, just want to be completely certain before I solder anything.

 

[Diynot]

Another idea for the “killing a fly with a cannon” approach would be to just disassemble the switch by lifting the metal tabs on the sides. Once those are loose you can dump out all the internal mechanism and either nipper the plastic body away from the solder lugs or just try and hit them with enough heat to drop them through the body and the solder pad

 

[jimilee]

Aside from the clr and the LED, you’ve got a everse polarity protection diode and a noise filter cap. The diode isn’t a must as long as you don’t plug in a center positive dc adapter. For the 100n, you can use a 100n across the dc jack. Probably isn’t necessary if you’ve got a clean power supply, but wouldn’t hurt. A 3pdt without the board won’t be a perfect.

 

[Bio77]

I've seen some videos of hotplates used for SMD soldering. You could take out the wires and components, then set the PCB on a hotplate. Switch should come out, board should survive for clean up.

 

[DAJE]

What I'm thinking is that I can put that diode and cap in line with the wire from the + lug of the power input. One leg of the cap to ground, the other to +v on the main PCB. Connect the cathode of the 5817 to one leg of the cap and then to the PCB +v input. Is that correct?

Then send another wire from the power +v through the CLR and LED to the footswitch.

And then the -v from power to PGND on the PCB. (First hole, bottom right cnr of PCB).

If I have that correct then the usual 3PDT wiring should work, and I can do that because that's what I usually do.

I want to keep the reverse polarity protection because the pedal is going to someone else - he's no dummy but I really want to be 100% sure.

 

[DAJE]

I've seen some videos of hotplates used for SMD soldering. You could take out the wires and components, then set the PCB on a hotplate. Switch should come out, board should survive for clean up.

Another thing I don't have. Though that is a good suggestion and I thank you for it.

I'm leaning pretty strongly towards just skipping the breakout board, anyway.

 

[PJS]

In your spot I would do that. Solder the diode and cap to the DC jack. If you have heatshrink then solder the CLR direct to the LED, solder a wire to it, and then heatshrink the whole lot into a nice tidy parcel.

 

[DAJE]

In your spot I would do that. Solder the diode and cap to the DC jack. If you have heatshrink then solder the CLR direct to the LED, solder a wire to it, and then heatshrink the whole lot into a nice tidy parcel.

I do have heatshrink and that's just what I was thinking. Thanks for your input.

 

[DAJE]

Well, I did what I said, and spent a couple of hours taking bits apart and putting them together differently, and now: horrible nasty squeal when engaged. No other sound. Still works in bypass and the LED is working, so at least there's that. Tomorrow I'll compare it closely to my earlier working version and see if I can spot any differences.

 

[DAJE]

It's now fixed and sounds great. Taking a couple of days off and coming back to it fresh was what it needed. That and an extra earth wire.