Auto Wah fail. Only hear a big buzz

[pillo10]

Hi, thanks you for your work.
My Snow White work bad. My problem is that I hear only a continuous buzzing sound when I press the swich. The buzz up and down by operating the BIAS potentiometer, but also up and down a bit by operating the RESONANCE, but less. I've been looking for the solution reading post and watching the electric scheme, but I can not find it. I checked everything but everything seems fine. I have printed the circuit and I have followed it too and I have bought again the main components to check one by one but it is the same. Any idea?

I have used the effectslayouts PCB http://effectslayouts.blogspot.com.es/2 ... towah.html

My knowledge of electronics are few, but I put a lot of effort. I have built several pedals and know more or less where I walk.

My voltage readings are:

The input voltage is 8,95 v.

LM3234
1: 3,95
2: 3,95
3: 3,95
4: 7,95
5: 3,96
6: 3,96
7: 1,81
8: 3,91
9: 3,95
10: 3,96
11: 0
12: 3,96
13:3,96
14:3,96

LM13700
1: 1.2
2: 0.25
3: 3.97
4: 3.96
5: 4.45
6: 0
7: 4.45
8: 3.80
9: 4.30
10: 5.47
11: 7.95
12: 5.47
13: 3.95
14: 3.95
15: 0.40
16: 1.20

2N5457
D: 7.95
S: 4.05
G: 3.59

BC550
C: 4.95
B: 0.58
E: 1.2

BC550
C: 4.95
B: 0.02
E: 0.50

Any ideas please
Thanks for your forum

[pillo10]

May the mistake be in the electrolitic capacitor 100 uf conections of my PCB?
Please may you verify it with the PCB and electronic diagram added? I think that it is wrong

Thanks

[pillo10]

Confirmed. It was the failure of PCB design. The + of capacitor C7 has to go in V + (red line of PCB).

Thanks