No signal from Wonder Drive build

[Jared]

I’m working on a Wonder Drive pedal. I got it all built out and I’m not getting signal through the pedal when the switch is on.
I’ve checked for solder bridges, and made sure all polarity in the separate components are correct.
I’m using a tester and going through the circuit and I’ve come to the point where the signal does not pass through; it’s after the first transistor in the signal. I’ve switched out transistor and the same thing is happening. No signal is coming out of pin 1 and progressing to the next resistor.
I’ve attached a picture to help visualize. (Green is good to go, red is where the signal stops)
Any help would be greatly appreciated!
Thanks!

 

[dlazzarini]

I’m working on a Wonder Drive pedal. I got it all built out and I’m not getting signal through the pedal when the switch is on.
I’ve checked for solder bridges, and made sure all polarity in the separate components are correct.
I’m using a tester and going through the circuit and I’ve come to the point where the signal does not pass through; it’s after the first transistor in the signal. I’ve switched out transistor and the same thing is happening. No signal is coming out of pin 1 and progressing to the next resistor.
I’ve attached a picture to help visualize. (Green is good to go, red is where the signal stops)
Any help would be greatly appreciated!
Thanks!

What IC are you using? If it’s the opa where did you acquire it?

 

[Jared]

What IC are you using? If it’s the opa where did you acquire it?

I am using an IC and it is an OPA from Smallbear electronics.

 

[Jared]

What IC are you using? If it’s the opa where did you acquire it?

OPA264AP

 

[dlazzarini]

OPA264AP

Ok just checking. Wanted to be sure it wasn’t some fake from eBay so we can eliminate that. I’m no pro at sorting through schematics but I’ll give it a go when I get a minute.

 

[dlazzarini]

OPA264AP

Just for shits and giggles do you have another dual opamp you could try out like a tl072 or a Lm4558 etc? I’ll say up front my troubleshooting skills are pretty limited as I’ve been extremely fortunate/lucky or both with all but my second build which turned out to be a cheap socket but I’ll try and look at the schem later

 

[Nostradoomus]

Post some pictures

 

[Jared]

Here are some images

 

[Jared]

Post some pictures

Thank you so much for your reply.
I've posted some pictures below for reference!

 

[Jared]

Just for shits and giggles do you have another dual opamp you could try out like a tl072 or a Lm4558 etc? I’ll say up front my troubleshooting skills are pretty limited as I’ve been extremely fortunate/lucky or both with all but my second build which turned out to be a cheap socket but I’ll try and look at the schem later

Sadly, I don't have an extra opamp available to try, though I'm not opposed to purchasing one if I need to. Thanks a lot for taking a look at that.

 

[zgrav]

Can you explain what you mean here: "I’m using a tester and going through the circuit and I’ve come to the point where the signal does not pass through "

Is your test a digital multimeter? Or are you using an audio probe? A DMM is good for testing your connections between parts on a PCB, but won't let you test "through" a part unless it is a resistor (and then it would measure the value of your resistor, assuming no other parts connected those two points).

Have you tried an audio probe? Easy to assemble from things you probably already have, and it will let you find out where your audio signal is being stopped. You can search on google for building an audio probe, and find a number of posts in the forums here as well.

 

[Nostradoomus]

I see lots of cold/suspect joints there.

 

[dlazzarini]

Sadly, I don't have an extra opamp available to try, though I'm not opposed to purchasing one if I need to. Thanks a lot for taking a look at that.

I doubt that’s what the problem is I just figured if you another it wouldn’t hurt to try. Now that you’ve posted pics I’d have to agree with nostradoomus. I would reflow a lot of those joints and clean your board with iso for starters.

 

[Jared]

Can you explain what you mean here: "I’m using a tester and going through the circuit and I’ve come to the point where the signal does not pass through "

Is your test a digital multimeter? Or are you using an audio probe? A DMM is good for testing your connections between parts on a PCB, but won't let you test "through" a part unless it is a resistor (and then it would measure the value of your resistor, assuming no other parts connected those two points).

Have you tried an audio probe? Easy to assemble from things you probably already have, and it will let you find out where your audio signal is being stopped. You can search on google for building an audio probe, and find a number of posts in the forums here as well.

Thank you for the advice!
I made an audio probe by instruction from a video I saw on YouTube. That’s what I used to trace the signal.

 

[Jared]

I see lots of cold/suspect joints there.

View attachment 5981

Thank you! I will try to fix that. This photo really helps.

 

[Jared]

C

I doubt that’s what the problem is I just figured if you another it wouldn’t hurt to try. Now that you’ve posted pics I’d have to agree with nostradoomus. I would reflow a lot of those joints and clean your board with iso for starters.

Cool, I will start there! What exactly is iso?

 

[Jared]

I doubt that’s what the problem is I just figured if you another it wouldn’t hurt to try. Now that you’ve posted pics I’d have to agree with nostradoomus. I would reflow a lot of those joints and clean your board with iso for starters.

I’m guessing the alcohol?

C
Cool, I will start there! What exactly is iso?

 

[zgrav]

you are right about iso --- isopropyl alcohol

 

[Jared]

I see lots of cold/suspect joints there.

View attachment 5981

I cleaned up the solder joints. It seems like some are still a bit rough but I think it’s because some of the wires are stranded and became a bit frayed when pushed through the joint. I also cleaned the PCB with iso.

There is still no signal. I used an audio probe as well. The result is the signal cuts out at the same point as before.

 

[zgrav]

Using your schematic and the place you circled, is there sound on pin 1 of the transistor when you touch it with the audio probe?

If NO, do you have sound on pin 2?

If you do have sound on pin 1, do you have sound when you touch the audio probe to one side of C2? If yes, do you have sound on the other side of C2?

Do you have sound on one or both sides of R7?

If you use your DMM to measure resistance, what is the resistance you have between Q1, pin 1 and each side of R7?