First Build Help: Coda Effects Black Hole, No Sound/No Led/Sound in Bypass

[Bucket]

1. Coda Effects - Black Hole, Sunn Model T preamp in a box
2. Build Doc
3. Built on printed PCB purchased from Coda Effects.
4. Followed the build doc to the t, no substitutions, no modifications. Of the two possible builds outlined I chose to do the "boost on switch" version. I also chose to use a (small footprint, true bypass, input grounded in bypass, provision for dropdown resistor) daughterboard for the 3PDT footswitch. This is also the version of the PCB that has the SMD JFETs pre-soldered.
5. N/A
6. No sound, LED does not light, sound in bypass

Schematic:


I have a multimeter but I'm very new to using it. Here are some voltage readings:
DC jack: 9.45
Q5 C: 0.00 B: 5.35 E: 0.00
Q6 C: 0.00 B: 4.01 E: 0.00
Q7 C: 0.00 B: 0.73 E: 0.00
Q8 C: 0.73 B: 9.46 E: 0.00
Q9 C: 0.32 B: 0.95 E: 0.95
D1 A: 9.45 C: 9.45

Here's a couple gut shots:



And for what it's worth, here's the daughterboard guide:


Any and all help greatly appreciated!

[eh la bas ma]

Hello, welcome !

I think there is a problem with your soldering. From the picture you posted, i can see there isn't enough solder on all pads.

The trick is to apply the tip of the iron on the pad 1 or 2 second until it's hot and then put some solder (not too much, enough to fill the pad) and finally remove the iron following the leg of the component upward, to form a dome shape (not a ball shape).

If you fail, you need a desoldering pump to re-heat the solder and suck it out.

The process needs to be done quickly to avoid overheating the pcb, like 4 or 5 seconds max.

Transistors and IC (Q1, Q2, etc) are sensitive to heat, so you have to be quick around these components when you apply heat around them. It's better to remove them if you can, but i see there are some smd components soldered on your build, so be carefull not to overheat them.

Iron set approximatly at 380 c°.

Soldering isn't easy at first but you will quickly get better at it !

After you reflow your pads, if it still doesn't work, please post a picture of the soldering side.

Edit : ...and don't forget to open the window, or use a fan to ventilate : you don't want to breath the fumes...

[Bucket]

Hello, welcome !

I think there is a problem with your soldering. From the picture you posted, i can see there isn't enough solder on all pads.

The trick is to apply the tip of the iron on the pad 1 or 2 second until it's hot and then put some solder (not too much, enough to fill the pad) and finally remove the iron following the leg of the component upward, to form a dome shape (not a ball shape).

The process needs to be done quickly to avoid overheating the pcb, like 4 or 5 seconds max.

Transistors and IC (Q1, Q2, etc) are sensitive to heat, so you have to be quick around these components when you apply heat around them. It's better to remove them if you can, but i see there are some smd components soldered on your build, so be carefull not to overheat them.

Iron set approximatly at 380 c°.

Soldering isn't easy at first but you will quickly get better at it !

After you reflow your pads, if it still doesn't work, please post a picture of the soldering side.

Thank you, I'll heat the iron back up and give that a shot!

Are there any pads you see in the photo that are especially low? I'll re-do them all but just curious.

[ElectricDruid]

Welcome Bucket!

Are there any pads you see in the photo that are especially low? I'll re-do them all but just curious.

There's two in the bottom-left marked "SW" with bare solid-core wires sticking out of them that seem to have been missed completely. Is that right?

[eh la bas ma]

I suspect they are almost all in need of reflowing. If there is enough solder already on the pad, simply re-heating them with the iron can help to move around the solder more evenly on the pad, you won't always need to add more solder.
The copper circle ( pad) should be fully covered with solder, but not too much, just enough.


Edit : most obvious problematic pads are circled in red. You can visit the build report section of the forum if you need some good exemples about how it should look.

Edit 2.  in green : a ball-shaped soldering, certainly a bit  too much solder. Not necessarily a bad contact, but never a good sign though.

Next to the green circle there are 2 pads (SW), I guess it's the led. looks like a leg is touching an other pad and this will make a short circuit . You might want to shorten these legs.

[Bucket]

Thank you both!

Welcome Bucket!

Are there any pads you see in the photo that are especially low? I'll re-do them all but just curious.

There's two in the bottom-left marked "SW" with bare solid-core wires sticking out of them that seem to have been missed completely. Is that right?

Yes, that was the LED which I had read should be done last - I've now soldered it and clipped the legs off.

I suspect they are almost all in need of reflowing. If there is enough solder already on the pad, simply re-heating them with the iron can help to move around the solder more evenly on the pad, you won't always need to add more solder.
The copper circle ( pad) should be fully covered with solder, but not too much, just enough.


Edit : most obvious problematic pads are circled in red. You can visit the build report section of the forum if you need some good exemples about how it should look.

Edit 2.  in green : a ball-shaped soldering, certainly a bit  too much solder. Not necessarily a bad contact, but never a good sign though.

Next to the green circle there are 2 pads (SW), I guess it's the led. looks like a leg is touching an other pad and this will make a short circuit . You might want to shorten these legs.

I really appreciate you detailing that for me. I've hit the board with my solder pump and I'm re-doing all that I can.

[eh la bas ma]

You're welcome.

I just remembered there isn't any "build report section" on this forum, it 's called "Pictures"

https://www.diystompboxes.com/smfforum/index.php?topic=36392.29560

But people don't really show the soldering side very often...it's more about artworks.
You can take a look at Joelo's work in his thread, I think it's pretty good, even perfect on most pads :

https://www.diystompboxes.com/smfforum/index.php?topic=128516.0

[Bucket]

I've desoldered and resoldered the worst connections, reflowed the rest, soldered in the led and clipped the legs, redid all the offboard wiring and still have the same problem. Sound only in bypass and an led that doesn't light.

Is there anything in the multimeter readings I posted that looks off? I'm not sure how to interpret the values. I've read a bit about continuity testing but I'm not sure how to go about doing that here.

[eh la bas ma]

I will let someone more experienced answer about your values with certainty. I do think they 're not what you would expect because there are probably still some issues with the soldering.

You said it's your first time using a multimeter (MM), so maybe something went wrong with your test. Just ask if you need some help with the voltage reading process, at first it can be hard.

Continuity test is a mode on your multimeter that allows you to check if two things are connected with each other, with the red and black probes. The meter rings when there is a connection. First thing is to find this mode on your meter.

Practically, with this mode you can check your soldering (verify that the current do pass between 2 points) and hunt for short circuits (two pads connected together when they shouldn't)  . You can also know with certainty wich pads are connected together.

For exemple, you are looking at R1 on your pcb and wonder wich pad is connected to R2 and Q1 : That's when you use the continuity mode to get the answer.
Other exemple, you see a suspicious soldering spot, it looks messy, you wonder if there is a short with an other pad close to it : same way to get your answer, does the meter ring or not.

Can you take a picture of the soldering side ?
Did you reflow the 3PDT switchboard too ?

Edit : About the led issue, the build doc mentions 10k for the LDR (it controls the led brightness)...never seen that before, I think that's why it doesn't light up. Try something lower like 4k7, 2k2, or 3k3, all should work. You can check if the led is ok with 10k using your MM set on diode mode (in this mode you can't burn it) : black on led negative pad and red on each LDR pads should turn the led on (one brighter than the other).

[Bucket]

I will let someone more experienced answer about your values with certainty. I do think they 're not what you would expect because there are probably still some issues with the soldering.

You said it's your first time using a multimeter (MM), so maybe something went wrong with your test. Just ask if you need some help with the voltage reading process, at first it can be hard.

Continuity test is a mode on your multimeter that allows you to check if two things are connected with each other, with the red and black probes. The meter rings when there is a connection. First thing is to find this mode on your meter.

Practically, with this mode you can check your soldering (verify that the current do pass between 2 points) and hunt for short circuits (two pads connected together when they shouldn't)  . You can also know with certainty wich pads are connected together.

For exemple, you are looking at R1 on your pcb and wonder wich pad is connected to R2 and Q1 : That's when you use the continuity mode to get the answer.
Other exemple, you see a suspicious soldering spot, it looks messy, you wonder if there is a short with an other pad close to it : same way to get your answer, does the meter ring or not.

Can you take a picture of the soldering side ?
Did you reflow the 3PDT switchboard too ?

Edit : About the led issue, the build doc mentions 10k for the LDR (it controls the led brightness)...never seen that before, I think that's why it doesn't light up. Try something lower like 4k7, 2k2, or 3k3, all should work. You can check if the led is ok with 10k using your MM set on diode mode (in this mode you can't burn it) : black on led negative pad and red on each LDR pads should turn the led on (one brighter than the other).

Interesting about the 10K LDR - I looked at a lot of previous build pictures for this pedal and didn't hear anything about changing it or anyone having trouble with the LED. I tested it with my MM but didn't get it to light with either LDR pad. I did get a "continuity beep" when touching the black probe to the positive pad of the LED and the red probe to right pad of the LDR but nothing when touching the left pad of the LDR. I did test the LED after taking things apart yesterday and the MM does light it so I know it's not a bad LED.

I continuity tested all my wiring and everything appears to be flowing properly there.

I did also reflow the switchboard. Here are a few photos I took while desoldering/reflowing things (I tried my best to avoid the glare of bright overhead lights) and a photo of everything re-boxed up:



Edit: I've just noticed in my photos two possible solder bridges! I don't know how I didn't notice them before. I'm going to try removing a bit of solder between those and report back.

[idy]

Solder on the pots looks especially dodgy.

[eh la bas ma]

I'm not surprised about the led. Some super-bright led may need a 10k resistor, regular ones are usualy paired with a 4k7.

Reflowing trick : The tip of your iron should touch both the remaining bit of the component's leg and the pad so the heat is applied to both at the same time.
As soon as you see the solder get liquid again, you remove the iron by moving it upward along the remaining part of leg, thus forming some sort of dome-shaped soldering. You can also add some solder during the process if you think there isn't enough to fully fill the  pad. 3 or 4 seconds max, especially around the smd parts.

Taking pictures and enlarging suspicious areas is a good way to spot shorts or any kind of problem that you can't easily see without a magnifying glass.

Don't bend the pots too often or too quickly to access the board or their legs will break.. make sure the circuit works first and then bend the pots back in position.

An old and dry toothbrush might be handy to clean the pcb.

Set all trimmers at 12' when testing if the circuit works.

Edit : you might have some trouble to work on the soldering side with all these pots. An alternative would be to cut the legs of the 3 pots that are in your way, and wire them to the remaining bits, or to the pads (cutting is easier than desoldering in this case). It won't make any difference as long as you use short wires, like 4 or 5 cm. The only downside i can see is that it will take a bit longer to screw them to the enclosure, because they must not touch each other...but that's easy.

[Bucket]

Well, this is embarrassing. I took everything apart for a second time, reflowed a lot, resoldered a few, and still had no luck. So I swapped the LED. That was it. It was the LED the whole time. For some reason I had been under the impression that the short leg went to the square pad.  Now the pedal is working perfectly! And I've gotten a lot of good solder practice! Thanks so much for the help and guidance.