Help with Aion FX Vulcan (Foxx Tone Machine clone)

[neiltheseal]

Pretty easy to blow a transistor. I've done it several times, and honestly on the last build, I think it was the transistors. Maybe a bad batch.


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I don't think it was a transistor. I put them into the sockets of another pedal and it worked fine. WIll look into the grounding issue.

[neiltheseal]

+1 on a missing ground connection.  Start by checking all your grounding - "even the LED won't light up..."

Put your meter on DC volts, and check the DC power jack inputs.  Red probe on +9,  black lead on ground.  If you have something close to 9V DC there, keep your red probe on the red +9V point, and touch the black probe to each of the other ground points on your schematic - on the PCB, the in/out jack shield lugs, etc. If all that's good, let us know.

This looks promising. I connected the red probe of my multimeter to the + of the 9v battery, then touch the negative of the battery with the black: reads about 8.3v. Makes sense.

Then with the red still connected to the + of the battery I touch the ground of the dc power input and it reads 0.51. This should surely read about 8v too right?

The LED is in backwards so about to fix that. However this should not really affect the circuit right?

[aion]

This looks promising. I connected the red probe of my multimeter to the + of the 9v battery, then touch the negative of the battery with the black: reads about 8.3v. Makes sense.

Then with the red still connected to the + of the battery I touch the ground of the dc power input and it reads 0.51. This should surely read about 8v too right?

That would definitely point to a grounding issue. You should have direct continuity between battery negative and DC jack ground, provided there's something plugged into the input jack (which makes the battery ground connection through the jack sleeve).

The LED is in backwards so about to fix that. However this should not really affect the circuit right?

Nope, it just wouldn't light up is all. No damage to the LED or the rest of the circuit.

[Bio77]

When you are testing the voltages with a battery you need an instrument cable (1/4 inch) to be plugged into the input jack.  There is a ground disconnect there to save the life of your battery when the pedal is not plugged in. 

Also, can you post a pic of all the wiring (both sides)?  Try to move the wires so it is clear where everything is going.

[neiltheseal]

When you are testing the voltages with a battery you need an instrument cable (1/4 inch) to be plugged into the input jack.  There is a ground disconnect there to save the life of your battery when the pedal is not plugged in. 

Also, can you post a pic of all the wiring (both sides)?  Try to move the wires so it is clear where everything is going.

Good idea i'll do that with the input.

Here are a few pics of the wiring and front/back of the PCB.

I have voltage when I check the DC output now. Not sure what was going on before.
https://imgur.com/gallery/IH7ZXtp

[neiltheseal]

I have also noticed that if I touch the ground on the guitar input lead to any of the other connections (which I assume are both input) then the LED lights up. Is this normal?

[neiltheseal]

I have voltage when I check the DC output now. Not sure what was going on before.
https://imgur.com/gallery/IH7ZXtp

Actually this depends where I connect the ground. If connected to the - of the battery then I get around 7.10v on the ground of the dc input.

Although I get about 7v on pretty much anywhere I touch, PCB, input/output jacks etc. Is this normal?

But I  connect the black lead to the ground of the input/output I get no reading.

[neiltheseal]

Thanks for all your help everyone. I have learned so much.

As expected, the issue was a simple one that is my fault: the battery wasn't properly connected!

I randomly tested it out with DC inout instead of battery and it worked! Sounds fantastic too.

I couldn't get the battery to work so just removed it. Happy to have a working pedal.