First time (newbie) builder - AionFX Azimuth no signal on effect

[adamtc]

Hey folks!

I'm super new to pedal building - this is my first one.  Most soldering build work I've done previously was XLR cables...

I did some searching of the forums and found posts with my same general problem, but I'm unclear if the solution would be the same.  You all seem super incredibly nice and helpful, so I figured I'd post and ask for help because I've got really no idea what I'm doing at this point.  I've added an image of the pedal I'm working with/multimeter so you can see what I've got.

What's working:

• Pedal will engage under 9v power supply and LED turns on.
• Pedal will bypass appropriately.

What's not working:

• 9v battery power does not function.
• No output from the effect - though it seems like the volume pot could be working because I can hear soft noise a bit louder when turned.

I've soldered/re-soldered the crap out of the components, so I wouldn't be shocked if I'd inadvertently damaged the board.  The only experience I have with a multimeter is a few videos about how to do continuity testing from YouTube.  If I've done those right, it seems like I've got a good connection from the switch PCB to the effect PCB, but something's up with the effect PCB.  I tried to walk myself through the electrical diagram, but the contiunity tests I tried didn't seem to line up with the information that was on the diagram and I got more confused.

I'd deeply appreciate any help you're willing to give a first timer!  Thank you!

[PRR]

Welcome!

I'm sure the gang will like to know WHAT that is. Yes, I see the brand, but he makes a LOT of kits, and nobody knows them all.

Also read and follow the Debugging Page:
https://aronnelson.com/diywiki/index.php?title=Debugging

[bluebunny]

Welcome.  Looking at the solder connections of the footswitch and the two pots we can see, I'd say your iron isn't hot enough?  Looks like the solder isn't flowing well.  (They should look like little Vesuviuses, but with concave sides.)

[antonis]

Hi & Welcome..

I presume your build is this one: https://aionfx.com/app/files/docs/azimuth_kit_documentation.pdf

Could you plz post a picture of both effect & switch PCBs dismandled..??
(i.e. item and soldering sides without cabling interconnection..)

[adamtc]

Welcome!

I'm sure the gang will like to know WHAT that is. Yes, I see the brand, but he makes a LOT of kits, and nobody knows them all.

Also read and follow the Debugging Page:
https://aronnelson.com/diywiki/index.php?title=Debugging

Thank you for the debugging page!  Reading through that, I've gotten all sorts of discombobulated when trying to work through the schematic.  I'm unsure if it's my inability to read a schematic right, or I screwed something up at this point.

Sorry about not throwing the name/link of the pedal in the body of the message - the one I'm working on is the Azimuth: https://aionfx.com/project/azimuth-dynamic-overdrive/

Welcome.  Looking at the solder connections of the footswitch and the two pots we can see, I'd say your iron isn't hot enough?  Looks like the solder isn't flowing well.  (They should look like little Vesuviuses, but with concave sides.)

I would assume two things are true:
1) I'm working with an old iron whose tip has seen better days....
2) I'm re-learning how to use a soldering iron

Specifically with the foot switch, I was really cautious how much solder I put down.  I soldered the IC/socket in upside down originally (oops) and it took some significant effort to get them out.  Then I got careful about how much solder I was putting on other parts.

Hi & Welcome..

I presume your build is this one: https://aionfx.com/app/files/docs/azimuth_kit_documentation.pdf

Could you plz post a picture of both effect & switch PCBs dismandled..??
(i.e. item and soldering sides without cabling interconnection..)

That's correct!  I've added a few images to this post.  The pots are currently blocking connections below them.  If I must, I can desolder the pots, but I'm a little gun shy to do that currently.  It doesn't seem like the pots are causing any grounding issue.

Thanks everybody for your welcome, generosity, and help!

[antonis]

I'd suggest to start form reflowing IN/OUT/DC jacks PCB..

[bluebunny]

Specifically with the foot switch, I was really cautious how much solder I put down.

The trick is not to be cautious, but to have the iron hot enough that you are confident of achieving a nicely-flowed joint done quickly.  Since you say you're relearning your soldering chops, have a bit of a practice on some spare vero.  Doesn't hurt to hone your skills. 

I soldered the IC/socket in upside down originally (oops) and it took some significant effort to get them out.

You of course know that the orientation of the socket doesn't make any difference to the workings of the circuit.  But it may have a negative impact on your sanity when you re-visit your build after a few months.   

[adamtc]

I'd suggest to start form reflowing IN/OUT/DC jacks PCB..

Frantically google's reflowing...   

I will do that today!

I soldered the IC/socket in upside down originally (oops) and it took some significant effort to get them out.

You of course know that the orientation of the socket doesn't make any difference to the workings of the circuit.  But it may have a negative impact on your sanity when you re-visit your build after a few months.   

....I....actually didn't know this... The doc gives a specific orientation for the socket (notched part of the socket towards the input/output jacks) and the IC orientation relative to the socket orientation.  Sounds like I wasted a bunch of time getting the socket/IC out and reset 

I'll work on the connections today and get them more cleaned up/clearly soldered and then report back.  Thanks!

[adamtc]

Okay cleaned up (at least, better than it was before) the connections with the switch and input/output jacks.  If I'm doing this right, I'm getting passing continuity tests up until I reach the first capacitor.  The first capacitor and resistor are supposed to connect, and I'm getting "OL" from my multimeter.  But, the first resistor is getting a solid connection to pin 3 on the IC, which it's supposed to!

Oddly for a bit I was getting a passing test from the capacitor to pin 4 on the IC, which is supposed to go to ground...?  I was confused, but now I can't replicate it.  I'm going to work on the connections to the resistor and capacitor shortly and report back.

[idy]

You won't see continuity through a cap; they block DC and only allow AC (signal) through. So you should see continuity up to cap, then continuity from the other side of the cap to pin 3.

Then you want to check voltages on the IC. All eight pins. You should see 0 on pin 4, close to 9 on pin 8, and close to 4.5 on the other pins. Pin 3 and pin 5 will appear lower because your meter loads them when you try to measure. If they read say, 3.5v but 1 and 2 and 6 and 7 read 4.5 you are good.

[adamtc]

You won't see continuity through a cap; they block DC and only allow AC (signal) through. So you should see continuity up to cap, then continuity from the other side of the cap to pin 3.

Then you want to check voltages on the IC. All eight pins. You should see 0 on pin 4, close to 9 on pin 8, and close to 4.5 on the other pins. Pin 3 and pin 5 will appear lower because your meter loads them when you try to measure. If they read say, 3.5v but 1 and 2 and 6 and 7 read 4.5 you are good.

Thank you idy!  I... hate to say I have no idea what I'm doing with electronics - but I didn't know the capacitor signal info and that's encouraging to me

So I tried to check my IC voltages and I have to be doing something wrong.  The documentation suggests putting the black end of the multimeter in one of the screw holes of the enclosure and then using the red end to test voltage - so I'm doing that.  I've flipped my multimeter to the 20V DC section (this is the selection in grey on the lower right of my multimeter in the photos above) and I'm touching the red end to each IC leg individually.

What I'm seeing is an inconsistent reading that has to be incorrect.  When I touch pin 1, the reading will show somewhere between 0.09 to 0.05 and then drop down to 0.0.  Pins 2-4 may do the same thing, but usually lower (like 0.03 and then drop).  Pins 5-8 show a flat 0.0

I watched this video to make sure I was doing things right: https://youtu.be/R0JNAIFNP8A

He shows that you can touch the input DC jack to get the input voltage, and my meter won't even read that.  So, again, I'm thinking I must be a bafoon doing something wrong but I'm not sure what.

Happy to upload a video or something if that helps.  Thanks for having patience with me, y'all.

[idy]

You need to make sure that you can get readings from your meter. Using the enclosure for ground is iffy, especially if the circuit isn't in a box!

Find the power in jack. Measure there voltage there. Maybe you can use an alligator clip or something to attach the black probe to a good ground spot. Maybe one of the jacks. Once you are sure you know what the supply is, and that it isn't being shorted out somewhere (that wold give you very low readings!) then probe the IC.

[adamtc]

You need to make sure that you can get readings from your meter. Using the enclosure for ground is iffy, especially if the circuit isn't in a box!

Find the power in jack. Measure there voltage there. Maybe you can use an alligator clip or something to attach the black probe to a good ground spot. Maybe one of the jacks. Once you are sure you know what the supply is, and that it isn't being shorted out somewhere (that wold give you very low readings!) then probe the IC.

Ok I clipped the black probe to the top of the output jack and then tested the underside solder point of the DC wall input jack and I see 8.9v. I can also get that reading at the large wire header attached to the i/o PCB and at the opposite end of that which is attached to the foot switch PCB.

The smaller wire headers running to the effect PCB give me that same weird low/no signal reading with both the footswitch on and off.  The IC gives me 0.0v for all pins.

Would this have anything to do with the footswitch solder points?  Or should I be looking elsewhere?

[idy]

The foot switch PCB and the main pcb have a set of three points that connect via header, on the left side, marked pcb in, end, +v. Do you see 9v on both ends, the footswitch and the PCB? We need to be sure power is getting to the PCB.

The footswitch itself doesn't (shouldn't) touch the 9v. Even removed you would still get 9v to the board if everything else is right. It just switches the jacks to the board and gives the LED its route to ground.

What about R8 on the footswitch board? Does it have supply V on one side and a little lower on the other?

[adamtc]

The foot switch PCB and the main pcb have a set of three points that connect via header, on the left side, marked pcb in, end, +v. Do you see 9v on both ends, the footswitch and the PCB? We need to be sure power is getting to the PCB.

The footswitch itself doesn't (shouldn't) touch the 9v. Even removed you would still get 9v to the board if everything else is right. It just switches the jacks to the board and gives the LED its route to ground.

What about R8 on the footswitch board? Does it have supply V on one side and a little lower on the other?

Gotcha, okay that's good to know and makes sense.

So, I see 8.9v on the left (v+) wire of the 4-strand wire.  I see 0v on the left side 3-strand wire (where there's PCB IN / GND/ V+) on the v+.  I get no voltage on either side of R8, but I see 8.9v on the right side (interior, next to the foot switch) of D1 and no voltage on the exterior side of D1.

So it looks like maybe there's an issue there?  If i'm reading the schematic correctly, D1 flows into R8 but I'm losing the output voltage on the diode?

Thank you for your help!

[idy]

I think you are getting the hang of this.
Yes, if you see power on the "outside" of that diode (the Anode, the side the power is attached to) but not the other side (the Cathode, with the stripe, where power goes to the board) there are two possibilities:
1) the diode is bad, backwards, not soldered in...
2) there is a short circuit on the Cathode side so all your power is going to ground. Solder gob, etc.

To check for #2, with the power off, test that Cathode side (the stripe side) for continuity to ground. You should not see that. You should see something like 20k, but it will take awhile because you will be charging up those two big caps in the power section. So you might see a near short, with the ohm value rising as the caps charge, leveling off (I am guessing) around 20k.

for #1, you could short the diode out, with a jumper. As long as you don't use reverse power, you will be ok. It is there for "reverse polarity protection."

[adamtc]

I think you are getting the hang of this.
Yes, if you see power on the "outside" of that diode (the Anode, the side the power is attached to) but not the other side (the Cathode, with the stripe, where power goes to the board) there are two possibilities:
1) the diode is bad, backwards, not soldered in...
2) there is a short circuit on the Cathode side so all your power is going to ground. Solder gob, etc.

To check for #2, with the power off, test that Cathode side (the stripe side) for continuity to ground. You should not see that. You should see something like 20k, but it will take awhile because you will be charging up those two big caps in the power section. So you might see a near short, with the ohm value rising as the caps charge, leveling off (I am guessing) around 20k.

for #1, you could short the diode out, with a jumper. As long as you don't use reverse power, you will be ok. It is there for "reverse polarity protection."

Okay good news and bad news - but we're heading in a good direction and I'm excited to see things working!

The diode was just a craptastic solder job.  I cleaned up the area with isopropyl alcohol to be safe and then re-soldered the diode.  Now I get signal on both ends.  Anode reads 8.94v, Cathode reads 8.7v.  I also get signal to R8 and voltage to the 3-strand wire and R6/R7 - and the IC is receiving power now!

The IC pins are getting less power than they should according to the documentation:

Pin 1 = 4.03 (Should be 4.68)
Pin 2 = 3.91 (Should be 4.68)
Pin 3 = 3.75 (Should be 4.68)
Pin 4 = 0
Pin 5 = 4.02 (Should be 4.63)
Pin 6 = 4.03 (Should be 4.67)
Pin 7 = 4.03 (Should be 4.67)
Pin 8 = 8.05 (Should be 9.61)

I'm still not hearing output of the pedal when the footswitch is engaged.  I've checked the schematic in reverse and the volume knob isn't receiving any signal, C5 (non-polarized capacitor) is receiving 4.01v on the terminal interior to the PCB (sorry, still learning terminology here...) but 0.0v on the terminal nearest the exterior side of the PCB.

I'll go ahead and double check this - but am I looking at the same issue I had with the diode that there's a short, breakage, or bad connection?  Or is that lack of power expected?

This just got way more fun again now that I can see things starting to function as they should (in a way) so thank you!

[idy]

Progress. Be careful to distinguish between "signal" and "power." We aren't listening to signal yet, just checking for power.

So the power goes through the diode and loses a schotky diode drop, a little over .2v. Then there is the decoupling Resistor, R8, that helps with the power filtering (it makes a filter with those big caps that come next) and that probably cuts the power a tiny bit, but you didn't mention that. I'm betting the other side of R8 is 8.05, what is getting to the chip.

Don't worry that your numbers are not exactly what the doc says; the doc says they were using a 9.8 volt supply, a little high. The important thing is you are getting close to your supply to pin 8, and that the ins and outs of the opamps are around half that. That is called bias. The sound is going to go up and down from that mid point.

I think next you need to make an audio probe. An instrument cable with 1/4 jack on one end (or what ever you need to plug into a tiny, not valuable amp) and the other end has an alligator clip to the ground wire and a cap (to block DC) leading to a probe. You put a signal into the pedal ( maybe a looper pedal or something so you don't have to keep strumming) and trace away. Is the signal getting to the PCB? To the opamp? Etc.

[andy-h-h]

Audio probe is a must have for a debug.   

Has anyone mentioned using flux to reflow?  Flux will make a massive difference if you have never tried it.  There's flux in solder, but it boils away pretty quickly - there's enough to solder the components the first time, but there's generally not enough for multiple reflows.  I use a flux pen as required. 

Check this video, about a minute or so in.  nerd alert.  https://youtu.be/tfIwHuGzUEk

[adamtc]

Progress. Be careful to distinguish between "signal" and "power." We aren't listening to signal yet, just checking for power.

So the power goes through the diode and loses a schotky diode drop, a little over .2v. Then there is the decoupling Resistor, R8, that helps with the power filtering (it makes a filter with those big caps that come next) and that probably cuts the power a tiny bit, but you didn't mention that. I'm betting the other side of R8 is 8.05, what is getting to the chip.

Don't worry that your numbers are not exactly what the doc says; the doc says they were using a 9.8 volt supply, a little high. The important thing is you are getting close to your supply to pin 8, and that the ins and outs of the opamps are around half that. That is called bias. The sound is going to go up and down from that mid point.

I think next you need to make an audio probe. An instrument cable with 1/4 jack on one end (or what ever you need to plug into a tiny, not valuable amp) and the other end has an alligator clip to the ground wire and a cap (to block DC) leading to a probe. You put a signal into the pedal ( maybe a looper pedal or something so you don't have to keep strumming) and trace away. Is the signal getting to the PCB? To the opamp? Etc.

Awesome!  Thank you for clarifying my language there and explaining the difference with input power

I'll have to get my hands on an extra capacitor.  Hilariously I have resistors lying around from arduino/breadboard projects - but no capacitors...

Audio probe is a must have for a debug.   

Has anyone mentioned using flux to reflow?  Flux will make a massive difference if you have never tried it.  There's flux in solder, but it boils away pretty quickly - there's enough to solder the components the first time, but there's generally not enough for multiple reflows.  I use a flux pen as required. 

Check this video, about a minute or so in.  nerd alert.  https://youtu.be/tfIwHuGzUEk

Funny you share that video - because that video is what got me to go out and get new flux.  I'm using it every time I'm checking the solder points!