Moar Overdrive: LED issues

[ferrinbonn]

Hi all. I've now built two Moar ODs and the LEDs aren't working on either one. Here's the story...

I build the first one as my first ever build. Everything worked, including the LED which was soldered to the board. I build it according the build docs, including the switch wiring.

I then build a second one, but this time used this 3PDT breakout to wire the switch (http://www.rullywow.com/product/3pdtv3-1a/). When I finished, the pedal worked perfectly except that the LED didn't function. I figured I had just made a mistake and did a bad solder on the LED and decided to live with it.

So now tonight, I went back to the original pedal with the working LED and moved it to a new enclosure with a new switch and new jacks (my work was very sloppy the first time and the jacks and switch were scratchy. When I moved it, I wired up the new jack using this type of 3PDT breakout board (http://www.bitcheslovemyswitches.com/#!/PCBs/c/10252302/offset=0&sort=normal). I turned it on and the pedal works fine, but now the LED that used to work perfectly no longer functions!

So now I'm stumped. Do these 3PDT breakout boards screw up the LED function on the main board since they have their own pads for a LED? I can't see why one would affect the other, but it's the only thing I can think of. Ideas?

[jubal81]

You're right. The LED on the main board needs a path to ground when the pedal is switched on.

Run a wire from the pad marked "L" to the resistor or LED pad on the 3PDT breakout that connects to ground when the pedal is switched on.

Turn the pedal on, then use a multimeter to test continuity on those pads to find the one that grounds.

[ferrinbonn]

Do I need to add the CLR to the breakout board as well then? I didn't add it on either board since I was using the LED pads on the main board.

And sorry for the noob question, but how do I test for the one that grounds? I did a quick search and most of the hits were about testing for ground in home wiring or with a car battery. I have a multimeter but I'm not sure what reading I'm looking for.

[jubal81]

Add R9 (CLR) to the main board. You only need one of those resistors.

On the multimeter, you need to set it so it beeps when the two probes touch each other. This is called a 'continuity' test, which you use to see if two points in a circuit are connected to each other. This may be a diode symbol setting on your multimeter.

If you touch the probes and it beeps, you turn the pedal on, touch one probe to a ground point, the touch the other probe to the different pads on the 3PDT breakout board and when it beeps, that's the one you wire to from the "L" pad.

[ferrinbonn]

OK, thanks for the instruction. So if R9 is already on the main board (which is has been all along), then all I need to do is add a wire from L on the main board to the LED that connects to ground on the 3PDT board?

I'm still confused though as to why this happened. Why does adding a breakout board on the switch cause the LED on the main board to stop functioning? The LED on the main board already had a path to ground or it wouldn't have worked in the first place, right? So adding the 3PDT board disrupts that path somehow?

[ferrinbonn]

Thanks Jason. This did the trick!