Build Your Own Clone Message Board

Hello! As you can probably see from the photo, this is my first build. Actually, I built the confidence boost without a hitch. Got the confidence to then go for the Fixed Wah. Here's where I'm at:

Bypass mode is fine. I get a clean tone.
When I stomp it on, the LED goes on, but the sound totally cuts out.

I'm not sure if it's related, but I did have two questions:

1) In the photos of the build it shows a wire connecting terminal 3 to 6 in the footswitch. But it doesn't actually mention to do this in the manual. Am I supposed to do this?
2) For the wire that connects terminal 4 to 9 on the footswitch, I wasn't sure if I did that right. When I run a continuity test w/ the multimeter from #4 on the PCB to terminal 4 and 9 on the foot switch, it beeps fine. BUT, it also beeps if I touch terminal 8 (and 4 on the PCB still). Should it be doing that? I made sure the wire doesn't actually touch terminal 8, but there still seems to be continuity between them.

What should I check next? I had a hell of a time getting the pots and toggles to line up in the enclosure so I'm hoping I don't have to redo that

Should I try to solder the resisters from the top of the board too? I can see some of the solder didn't flow all the way through.

Or if there are any tips on what I can do w/ the multimeter to help narrow it down, that would be appreciated!

Thanks.

Update: I am not sure what I did, but I get sound when it's engaged now. But it's the clean sound. No different than when it's in bypass. What might that mean?

With regard to your two questions, neither is related to the problem you're having. The 3-6 jumper is not needed for the circuit to function; it's just a means of grounding the input to the effect circuit when the effect is bypassed and minimizes switching noise. And 4-9-8 lug continuity when bypassed is exactly what you want to see.

What IS a problem is your soldering quality, and you're already aware of that. There is visual evidence of inadequate solder application on some of the pot solder pads, while others are blobby, indicating lack of flow. The solder pads should be completely covered with solder and the joint itself should be shiny and conical in shape, like a miniature Hershey Kiss. If the solder joints on the top of the PCB look blobby or starved, then many of the component solder joints underneath certainly will, as well. As you pointed out, a little bit of the solder from underneath should "peek through" the eyelet on top, so a dark hole is to be avoided. Also, there shouldn't be stray wire strands sticking out of any solder joints, as these often lead to power or signal shorts. But the worst thing I see is the joint at eyelet 7 on the PCB, connecting to lug 7 of the footswitch. That one looks like it may not be making contact at all, and it's the return path for the effect signal exiting the PCB circuit.

In short, your soldering needs some dedicated improvement work. I would start by working through this process carefully: viewtopic.php?f=9&t=52188

Some additional useful info is contained in these threads:

viewtopic.php?f=9&t=52211

viewtopic.php?f=9&t=6401

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Hard to say at this point, but issues that come and go (1) are usually due to wonky solder connections, and (2) usually come back again. And again, and again, etc., unless fixed.

BTW, your footswitch is in need of special attention. As a novice, I wouldn't expect your F/S to look like the one below, but it should be much closer to that than its current state. There's a thread about this subject available at viewtopic.php?f=50&t=33293.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

OK, thanks. I will backtrace a bit and see if I can find success. Thanks for the replies.

One thing I forgot to mention, during a desoldering I accidentally removed the pcb donut where the 4.7u capacitor goes. It's intact just fine on the other side of the board. Is there something I need to do to correct this or will soldering into that hole be OK still?

Not a problem, because there's no trace connection on the component side board there. As long as the eyelet & solder pad on the back side are intact and you have a good solder connection to both legs of that cap, you're OK.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thanks! I'm wondering if you have any good references for good desoldering technique? I want to redo every component that has hook-up wires involved as I didn't properly tin them the first time. Here's my foot switch. I'm having a hard time getting the solder off to expose the hole. I'm using a desoldering wick. I am placing the wick over the solder then heating the wick and solder and trying to wipe off. But usually the solder just flows back into the hole.

Do I risk breaking these components from this process? I'm not sure how much heat it takes to make one fail. I try to not keep the iron touched for more than 2-3 seconds, but that doesn't always seem to work.

I think this is good practice for me, but at the end of the day I'd hate to have rebuilt it to find out I hosed a component in this process!

I've read the other resources you all provided and I feel a bit more confident for round 2!

Chem-kwik solder braid. It’s crazy good.


Sent from my iPhone using Tapatalk

_________________
Pedal building is like the opposite of sex. All the fun stuff happens before you get in the box.

Go on YouTube and search on "desoldering circuit boards"--plenty of videos on the subject.


Sounds like you may be using cheap de-soldering braid. Good quality de-soldering braid is a must. The best stuff I've ever found is this: https://www.amazon.com/gp/product/B008O9VLA2/. It soaks up molten solder like a sponge, quite literally.


Keeping the iron tip contact to 2 - 3 seconds is good practice. Too much heat can damage some components, though resistors and caps are pretty rugged. Footswitches are prone to internal damage if you apply heat for too long--the plastic holding the metal contact pieces can melt and they can get displaced. Apply heat to the joint, remove the wire, let it cool for a few seconds, and then remove the residual solder from the lug either with braid or a "solder sucker".

The trickiest things to de-solder are components with 3 or more connections to the PCB. But that shouldn't be necessary here. We can provide further guidance for this situation, should it become necessary.

One other tip, though it may sound a bit counter-intuitive: keep the tip of your iron freshly tinned when de-soldering. This facilitates rapid heat transfer and is particularly important when using braid. A dry iron tip is not your friend when de-soldering!

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

My”if all else fails” go to is heat up the solder and quickly blow it with your mouth with a short burst of air. Just be mindful of what’s below it. Silly, but it works.


Sent from my iPhone using Tapatalk

_________________
Pedal building is like the opposite of sex. All the fun stuff happens before you get in the box.

Hi all. So I reflowed all the solder and I redid all the hook-up wiring. I know it's not perfect, but I'm learning.

Unfortunately I've got the same outcome. Bypass works fine, and when engaged the LED lights up but no sound at all.

What might the next troubleshooting steps be? Is there some technique I can use to test the current at various points?

One thing I noticed, which may be OK, is that some resistors show a different value in the circuit. e.g .the upper right 22k is showing me about half of that resistance when in the circuit.

If anyone can share a post or some thoughts on the next step of debugging this I'd appreciate it. Thanks

A good next step would be to check DC voltage levels on the pins of the two ICs. Do you know how to do that?

Incidentally, a photo or two of the solder side of the board would be useful.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thanks, I’m not exactly sure. Do I remove the IC and check the voltage of the socket? Which pins?
Thanks.

Leave the IC's in the sockets, because the voltages will be used to determine if they're working correctly or not. If we need to pull the chips and measure the sockets themselves, that can be done later.

To measure the DC voltage level on the IC pins, set your multimeter to the DC voltage mode; use the 20VDC range setting if it's not an auto-ranging meter. Put the black probe into one of the corner screw bosses of the enclosure--this is your ground connection. Then touch the red probe to the point that you want to measure. Of course, your power source needs to be connected and there needs to be a cable in the input jack. Measure each pin of both ICs and report your results here. See image below for now the pins are numbered.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thanks!

Smaller IC:
1: 4.5v 8: 9v
2: 4.5v 7: 8.5v
3: 4.1v 6: 4.95v
4: 0.2mv 7: 4.95v

Larger IC

1: 0.74v
2: 1mv
3: 3.4v
4: 3v
5: 131mv
6: 0v (nothing)
7: 131mv
8: 1.6v
9: 1.5v
10: 16mv
11: 90mv (goes up higher as long as i keep the probe on)
12: 40mv (goes up higher as long as i keep the probe on)
13: 3v
14: 3.4v
15: 1mv
16: 0.74v

Hopefully I got all those right. The larger IC was a bit different in that it had one pin (6) without any voltage at all. And pins 12 and 11 were hard to get a read on as it kept going up as long as I would keep the probe on.

Thanks.

The smaller IC is a dual op amp, and those values look good except for pin 7, which should also be in the 4.5 - 5V range. Suggest you recheck that one.

The larger IC has a lot of values that appear far from what I see on my own functional EF/FW. Here's how mine reads:

1 - 0.84
2 - ~0
3 - 4.97
4 - 4.98
5 - 0.56
6 - 0 (Gnd)
7 - 0.57
8 - 5.02
9 - 4.95
10 - 0.62
11 - 9.96
12 - 0.63
13 - 4.97
14 - 4.98
15 - ~0
16 - 0.84

Most concerning from what I see in your numbers is the value for pin 11, which should be the same voltage as your power source. I would recheck that first, and if you still get a low value, pull the IC and check the socket voltage.

I'd still like to see photos of the solder side of the PCB.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thanks. I got a better reading on pin 11 and indeed it's 9v. However on the op amp, I'm still getting pin 7 at 8.5v.
I've attached a picture of the other side. Again, many thanks for walking me through this. I'm learning a lot from the process and hopefully the next build will be smoother!

Also.... I was wondering if there’s any sure way to test for cold solder joints. I thought maybe I could test continuity on the back of the board but that doesn’t seem to work. Any other way to narrow it down?
Also I’m wondering how sensitive these boards are. Could I have fried any components or the pcb itself from the troubleshooting? Like touching components while it has 9v connected. Like i said , I’m new to this and hopefully I didn’t make any irreversible mistakes!

Thanks again.

... just reflowed all the solder, but still no effect. Only bypass. I’m out of ideas.

In addition to re-flowing the solder joints, I would recommend doing some additional clean-up on the board. I also recommend using a magnifying device of some sort to inspect the board as you do this. Remove any stray bits of solder that you see, and look for & remove any solder "bridging" between adjacent solder joints if they aren't already connected with a trace on the board (we can help you identify those, if you're not sure). Also, I see quite a number of joints with "tails"--component lead or wire ends sticking up through the joint. These should be trimmed down to the top of their respective joints, since they can conceivably cause shorts. Be sure to gently bend up the two pots in the middle of the PCB and inspect there as well.

Since the back of the PCB looks pretty sticky, I'd also recommend cleaning it off with isopropyl (rubbing) alcohol. If there is a noticeable build-up of singed, blackened or otherwise degraded solder mask present, scrape it off with the blade of a small screwdriver and brush off the loosened residue with an old toothbrush before doing the IPA wash. It generally takes 3 or 4 rinses to get the gunk off. A Q-tip is useful for cleaning up particularly cruddy or hard-to-get-at areas, as is the toothbrush. Make sure that the board dries completely before re-energizing the circuit or doing any additional soldering on it.

If the pedal still doesn't work, your best shot for further troubleshooting is a SIGNAL TESTER. Do you happen to already have one?

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thanks. Will do this tomorrow.
I do not have a signal tester. Is that something that can’t be done with a multimeter?

No, it's something completely different. It's a simple and inexpensive device for testing for the presence of guitar signal at various points along the effect circuit and helps you pinpoint where the problem is occurring. You can buy one from BYOC at the link in my previous post, but they're also very easy to make. The instructions for constructing and using one are here: http://byocelectronics.com/signaltesterinstructions.pdf

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

OK, thanks again. Did the visual inspection and IPA bath, but same results. However, I did find a possible bad solder joint where we have a 4.7 uf capacitor. I am not 100% sure, but it may be missing the eyelet there. I did re-solder it. Is there some test I can do w/ the multimeter to ensure this capacitor is functional in the circuit? In the meantime I will get a signal tester.

Thanks.

Good find! I would agree that it definitely appears like the solder pad is missing on that eyelet. That's very important because:

1. ...that solder pad on capacitor C2 connects to a trace running to pin 1 of the dual op amp (IC1). If the pad is indeed gone, that connection is broken, and...
2. ...since pin 1 is the output of that half of the op amp, that would mean no signal from there through the following part of the circuit.

Refer to the labeled PCB diagram and the circuit schematic shown below.

So you may have pinpointed the cause of your problem! Fortunately, the fix is quite easy. What you want to do is to run a jumper wire from the leg of that 4.7uf cap protruding from the pad-less eyelet over to the solder joint of pin 1 of IC1. See my marked up version of your photo below. Just "tack solder" a short piece of wire (I'd use a piece of component lead clipping) between those two points, taking care that it doesn't touch any of the other adjacent solder joints. Try that and see where you're at.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2