Please Help. Simple Pedal is defeating me

olewaylon · August 13, 2015, 10:13:48 PM

So I am Doing a simple A/B switch with LED. I have followed the diagram and re wired this project twice with the same result. Please give me some ideas of what is causing this to malfunction. After the first failure I didn't mess with the LED and just used 2 of the 3 sides of the switch to get the switching function to work so please ignore the not connected LED. When i plug in to the Box sound only goes through the A output. when i press the button nothing happens.

The welds don't look great but mine always look bad and have worked on other projects. I have fat fingers.

Note - LEDs are not connected waiting to figure out problem with switching first.

Substitution - I used a stereo jack for the input because that all RadioShack had in stock. The other two are Mono. I wouldn't think this would be a problem but please ket me know if it is.

Used the Schematic from Youtube.

Edit: Subject Spelling Corrected

olewaylon · August 13, 2015, 10:14:49 PM

Edit: Sorry let me retry the photo upload

olewaylon · August 13, 2015, 10:20:25 PM

olewaylon · August 13, 2015, 10:26:46 PM

digi2t · August 13, 2015, 11:06:51 PM

I might be wrong here, but it looks to me like you have twisted what is represented by the yellow and purple jumpers on the diagram together.

The short purple jumper, and the short yellow jumper, shown between the left side switch lugs, are two separate wires, and should not inter-connect. If they were supposed to connect together, then a black dot would have been used to indicate connection (like on the jack tabs).

Like I said, it's what my eyes see.

olewaylon · August 14, 2015, 12:03:39 AM

The picture is a bit lousy, I agree it does loo like that. I actually have the purple jumper twisted with purple line coming from output B Tip. Would this create trouble? The Yellow jumper is the red wire flat on the switch. It might show better in picture below. Thank you for looking at my diagram, I appreciate all input.

mth5044 · August 14, 2015, 12:23:13 AM

That switch looks like it's been through a lot. Use your multimeter to make sure the correct lugs are being connected and disconnected using either the continuity measurment or a low ohm setting to make sure there is minimal resistance.

Follow how your signal should flow, flip the switch, measure again.

olewaylon · August 14, 2015, 12:37:38 AM

I agree mth5044. The switch only 2 days old but but been through a lot. (soldering and desoldering). I was actually wondering how often switches come from factory broken. I got this in a kit with a case from Hong Kong. I will find my multimeter and give that a try.

They way I understand one side should be powered and swaps sides when button is pressed. That makes me wonder why the A output flows even when button is being pushed. Im pretty new to this and pardon my ignorance.

Thanks for your help

olewaylon · August 14, 2015, 02:40:00 AM

Ok I tested all of the connections with my multimeter and all of the welds appeared to be good. What I noticed is the switch is sending power to the top side of the switch but when I push the button the orientation doesn't change. So the bottom row shows no connectivity to the middle row. I assume when you hit the button the orientation is supposed to switch from top to bottom? Im wondering what to check now. could it be the metal case grounding it in some weird way? This is the first time I've used 3PDT switch so I'm kind of clueless on this. The button is just supposed to work with no power? I wouldn't think that not hooking up the LED would effect anything by leaving the right row empty.

StephenGiles · August 14, 2015, 06:27:16 AM

Peddle.......I love it!!!!!

induction · August 14, 2015, 06:40:39 AM

Quote from: olewaylon on August 14, 2015, 02:40:00 AM
Ok I tested all of the connections with my multimeter and all of the welds appeared to be good. What I noticed is the switch is sending power to the top side of the switch but when I push the button the orientation doesn't change. So the bottom row shows no connectivity to the middle row. I assume when you hit the button the orientation is supposed to switch from top to bottom? Im wondering what to check now. could it be the metal case grounding it in some weird way? This is the first time I've used 3PDT switch so I'm kind of clueless on this. The button is just supposed to work with no power? I wouldn't think that not hooking up the LED would effect anything by leaving the right row empty.

Sounds like your switch is cooked. Replace it, and be gentle when soldering the new one. Don't let the soldering iron touch the lugs for more the 1 second at a time.

mcknib · August 14, 2015, 08:40:57 AM

You should as you correctly say get a connection from the common (middle row) to the top row and when pressed common to bottom row. So when pressed 1 and 2, 4 and 5, 7 and 8 should connect and when pressed the other way 2 and 3, 5 and 6, 8 and 9 connect

Before you condemn it make sure when you're testing it you're getting a good connection on the lugs with your probes sometimes with solder on them you don't always hit a bit that'll give you a good connection so try to get your probes in the lug holes or a bare part first if it beeps it's good if you put it on different bits of the solder joint and get no beep could be a bad solder joint so re flow it and test again.

If you get 2 good poles you can still use it forfeiting the LED which you could do without anyway you'll know what output it's on whether it be connected to 2 pedals or 2 amps you'll know which one's active. So if you play and get delay when it should have gone the other way...click it...take the applause and carry on regardless! (sorry just had to put that in!)

Continuity test all of your connections and grounds using your diagram e.g. input jack tip to 3pdt lug 2 yellow wire from lug 1 to 6 etc to make sure everything is connected that should be. To continuity test your grounds just put the black probe in an enclosure screw hole and touch your ground connections with the other probe.

This is all assuming you have the continuity function that gives an audible beep on your meter if not do as Matt says use the resistance function here's a wee PDF I did a while back for continuity testing:

http://www.guitarpcb.com/PDF%20Files/Checking%20for%20Continuity.pdf

I notice you don't have the LED legs insulated going through the enclosure I can't see if you've got a plastic bezel in there It won't be causing your problem. Just for future reference don't have any metal parts touching the bare enclosure that shouldn't you can use bits of stripped insulation from your wires to put over the legs of components to insulate them

olewaylon · August 14, 2015, 12:40:08 PM

Mcknib that post is very helpful at helping me to understand what is going on and will rely on PDF in future. I did as you advised and tested all grounds and connection point. All of them appear functional and to have a strong connection.

When testing the top row and middle vs bottom row and middle I notice that no bottom poles connect to any middle poles. Also no top poles disconnect from any middle poles (always connected). Even if the bottom row went bad shouldn't the top row still disconnect when button is pushed?

Whats surprises me is the majority of soldering and joints were on the top row so I would think that would go bad first. I'm not sure if I had a bad switch to begin with but I will always check my switches before I start a project from now on.

mth5044 · August 14, 2015, 01:22:43 PM

Definitely sounds like a busted switch. It looks like you over heated it often, lots of burned parts, the red stuff deformed. Also lots of solder on there. You really want to only head it for a few seconds. Make sure you are heating both the lug and the wire, not just the solder. Lots of soldering posts/tips on this forum, have a search!

Your wire also looks to be a very low gauge - might be easier for you to get a higher gauge/smaller wire.

mcknib · August 14, 2015, 06:39:57 PM

With too much heat as everyone says you'll damage the internal switch mechanism and it sounds like that's what's happened to yours if the insulation starts melting on the switch and you press too hard the lugs will go inwards and cause damage.

As Matt said the wire does look thick you want 24 gauge solid or stranded core I use 24 gauge pre bonded stranded core wire that's about as thick as you'll need it for low voltage pedal circuits.

Here's another PDF link you should find useful and hopefully informative done to help people avoid some of the mistakes I made when I started with regard to ordering components and what not:

http://www.guitarpcb.com/PDF%20Files/A%20Beginners%20Guide%20to%20Effects%20Pedal%20Components.pdf

blackieNYC · August 15, 2015, 10:40:01 AM

I am a very experienced solder jockey, but I remember having blown out my first 3p2t stompswitch. The connections inside can "open" - that is, the pin that you see becomes disconnected from the works. Too much heat for too much time. If you have to fix a mistake, or add a 2nd wire, let the thing cool off.

olewaylon · August 15, 2015, 11:25:01 PM

Yeah I agree with what everyones saying. Im sure I got a over ambitious and cooked the switch, I will be more careful when I receive my new one. With regards to the wire, I think the thickness definitely made it worse. The gauge was too big to fit in the holes creating a difficult solder job. I will get some thinner wire also. Thanks again for all the help, I will post results after I get the new switch.

olewaylon · August 15, 2015, 11:46:56 PM

where do you buy your wire from? RadioShack has very limited supply and Amazon doesn't seem to have much for Pre bonded wire.

LightSoundGeometry · August 16, 2015, 12:15:17 AM

I just got some Small Bear wire - pre bonded sampler pack ..I cant stop raving about it because I tortured myself with cheap stranded wire for too long ..it made a frustrating part now easy .

olewaylon · August 31, 2015, 05:02:49 PM

I finished the project and got a new box to put it in. the smaller wire made it 100% more easy. Thanks for everyones help.

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Please Help. Simple Pedal is defeating me