Aion azimuth no signal to pin 1

[Acschoolar]

Hello all!
   Brand newbie here. Building aion azimuth for a first build. So final pass through and led work but no sound when pedal is engaged. I saw another great thread of a similar nature here and started to work the problem from that info. Got as far as building an audio probe and got signal up to ic pin 1. No volts measured on any ic pin, but do have sound coming through on pin 3. Not sure what's between pin 3 and pin 1 that I can check. Again, very first build, but thought that I meticulously followed every step of the build. Any guidance would be greatly appreciated. Thank you!

[idy]

pin 3 is the input (non inverting or +) and 1 is the output. So sound goes in to the chip and dies.

We must know the voltages of the pins. We want to see:
0 on pin 4
9 "ish" on pin 8
the rest at mid voltage (around 4.5), with pin 3 reading a little low because your meter will load it.

[antonis]

Hi and Welcome..

Not sure what's between pin 3 and pin 1 that I can check.

The half of the whole IC..
(left side amp)

Got as far as building an audio probe and got signal up to ic pin 1.

Check for continuity between IC pin 1 & R4..
Check for signal on right leg of R4 (joint of R4 and Tone pot lug1/2..
Check for signal on IC pin 5 (if C4 is shorted, signal dies here)..
Check for signal on IC pin 7 (and/or pin 6)..
Short C5 (via a jumper) anbd check for signal on Volume pot lug 3..



P.S.
Focus on R4/Tone pot/C4 circuitry..

[idy]

Yes welcome. And if...

No volts measured on any ic pin,

...then no power to Opamp. Why? where does the power stop?

[antonis]

No volts measured on any ic pin,

...then no power to Opamp. Why? where does the power stop?

I think OP means that he didn't stage any voltage measurement..

[Acschoolar]

Hello all, I thank you for your replies. I should've started out by saying I'm totally ignorant about schematics, builds, layouts etc. all of it. Also, I've never posted on any forum ever- it took me a while to figure out how to post and reply. Anyway, I've come up to speed a very little bit on schematics. Seems like signal enters ic pin 3. Exits pin 1. Pin 2 is where some manipulation of signal happens, but exits the ic at pin 1.
  I have audio probe signal at pin 3, but no signal at pin 1. In fact, no signal to any other pin other than 3. To me, that means it's interrupted somewhere in the branch that's associated with pin 2?
To answer some of your questions:

1) When I put ground probe on chassis and touch any ic pin, I get no reading (multimeter set to dc20.) I assume that means no power to opamp, but don't know where the power stops.
I made an audio probe and get sound when touch pin 3, but no measured voltage. How can that be?

2) I have continuity from pin 1 to r4 (right leg)
   No audio probe sound at r4 (right leg)
   No audio probe sound on pin 5 or 7
   Don't know how to short c5

Again, thank you all for the help and the patience!

[idy]

As I said, signal goes into the opamp and does not come out. You say there are no voltages to the opamp. That would do it! You need to fix that first of all!

So voltages. It may be the chassis is not well grounded. You need to:
set the Multi-meter on Volts DC, and the right range, probably 0-20.
The black probe needs to go to ground. Maybe the ground on the jacks. Maybe use an alligator clip so you can focus on the red probe.
Then you probe the pins. (My earlier post tells what you want to see there.)

First you make sure there is power. Is there power on the DC jack?
How about the little board that has the footswitch and etc? The soldering there looks dodgy....There is a polarity protection diode there. The power should be going through there and the 100 ohm resistor next to it, through the ribbon cable.... And then to pin 8 of the IC.

The quick and dirty of the opamps is: they have two inputs (+ and -, non-inverting and inverting) and an output. The connection between out (pin1) and - input (pin 2) produces negative feedback and controls the gain. That's why the gain control goes there, bigger resistance =less feedback and more gain. Those diodes and MOSFETs will conduct and cut the gain above a threshold, that's where the clipping or distortion comes from.

[PRR]

> I don’t know where the power stops.

I got no water at the upstairs sink.

How do I figure where the water stops???

(Let's use electrical techniques, ignoring the puddles.)

First: where dose water come FROM? Maybe a river or well. Go look, is it wet? (A lot of people are looking down wells this dry year.) Probably to a pipe. Disconnect points, or drill test-holes.... is there water at the house entrance? At the basement pipes? At the kitchen sink? (Yeah, we'd check that first...)

You have a battery? A power supply? Is there power in it?

With water, you can bet it always falls to the floor. Electricity can go anywhere. Your voltmeter probes can go to "any" two places. But for sanity, usually many-many places are tied together and called "common" (or ground, but don't take it literally). Put your black probe there. Carefully touch other points with your red probe.

[anotherjim]

There isn't much you can get wrong with this build with the helpful printing on the board. The ribbon cables joining things up means you can't get crossed wires. I think the problem is going to be pretty basic.

The fact that you get sound in bypass isn't something miraculous. In bypass, signal is passed through by the mechanical footswitch and that will work without any power at all.

I don't know what you are using to power it.
If a battery, that could be bad.
If a DC pedal power, this might be wired wrong or you have the wrong polarity on the 2.1 plug. That big diode (D1) will stop power if the DC supply + and - are reversed.

[antonis]

I made an audio probe and get sound when touch pin 3, but no measured voltage. How can that be?

Sound is considered AC and measured voltage on pin 3 is DC..
In case of well powered circuit, you should measure about +4.5V DC (for DMM set on DC range) and some tens to hundreds mV (for DMM set on AC range) on pin 3..

[duck_arse]

Hello all, I thank you for your replies. I should've started out by saying I'm totally ignorant about schematics, builds, layouts etc. all of it.

multimeters can be tricky things for newcomers. we often ask to see a photo of the meter in use, and that sometimes provides clues when there is no volts as to why there is no volts.

[Acschoolar]

Hey all,
   A big thank you! It works great now! Each of the replies was helpful to this total rookie. I followed the power path and found a cold solder. Quite a learning experience for me. Thanks again.
Ps: I think I remember reading on another thread that fixed problems should be marked as solved. Is that true and, if so, how does one go about doing that?

[idy]

It is wonderful when they fire up. For some people pedal building is like golf, and troubleshooting just having to take a shot from the rough. Congratulations.