MadBean Mimik Help

[GreySuits]

Hi All,

Background:  I'm pretty much a newb to both pedal making a soldering.  I have successfully built a Bass Fuzz (using Vero) and have bread boarded a bunch of stuff, but my soldering is not great to say the least. 

I just finished putting together the MadBean Mimik delay PCB (see below) and I am getting zero sound when I click the pedal on.  When the pedal is off I can hear the guitar just fine. Here are photos of both sides of the PCB.  Some of the holes were really close together and I was worried about shorts so I took an exacto knife between the leads to try and cut any shorts.  I also double checked the capacitor and resistor values and that the capacitors and diodes are put in the correct orientation (ie +/-).  Finally I checked the voltage of the ICs (see below).  Can any one help me trouble shoot this?





Here is all the info that came with the PCB:

http://www.madbeanpedals.com/projects/_folders/1590G/pdf/Mimik.pdf

Here is the schematic and the PCB layout:




Here is what the voltage outputs should be:


and here are the readings I got:
IC1
1: 4.41
2: 4.43
3: 4.38
4: 0.03
5: 4.42
6: 4.43
7: 4.43
8: 8.82

REG
I: 8.86
G: 0.02
O: 5.12

IC2:
1: 5.12
2: 2.57
3: 0.04
4: 3.96 0.04
5: 2.44 3.96
6: 0.74 2.44
7: 0.74 (I get a different reading with 7 and 8 every time i measure them any where from 0.7 to 1.0)
8: 0.86 (see above)
9: 2.56
10: 2.57
11: 2.57
12: 2.57
13: 2.57
14: 2.56
15: 2.57
16: 2.57

[Slowpoke101]

The voltage on IC2 pin 4 is the clue. It is supposed to be at 0V.
It is also supposed to be connected to ground. Perhaps you have a broken PCB track going to pin 4.
The easiest thing to try is to link pins 3 and 4 of IC2 together and see if it works.

[GreySuits]

The voltage on IC2 pin 4 is the clue. It is supposed to be at 0V.
It is also supposed to be connected to ground. Perhaps you have a broken PCB track going to pin 4.
The easiest thing to try is to link pins 3 and 4 of IC2 together and see if it works.

Thanks!  Should I just Solder a wire between pins 3 and 4?

[Slowpoke101]

Yes, just solder a small wire link between pins 3 and 4. Or bridge them with some solder (not the best technique but fast ).

Something to keep in mind is that you used a knife to "cut any shorts". In doing so you may have damaged some PCB tracks running between component legs so don't be too disappointed if it still does not work after bridging the pins on IC2.

[antonis]

Strange indeed..!!

Pin 4 of IC2 socket seems to have very clear & firm soldering with no "cuts" or anything similar to PCB ground plane..

[duck_arse]

did you wire the bypass and in/out jacks as well? can we see pics of if you did, please?

[GreySuits]

The voltage on IC2 pin 4 is the clue. It is supposed to be at 0V.
It is also supposed to be connected to ground. Perhaps you have a broken PCB track going to pin 4.
The easiest thing to try is to link pins 3 and 4 of IC2 together and see if it works.

Sorry, turns out I transcribed the voltages incorrectly on my initial, pin 4 is getting around 0V (sorry should have doubled checked these after I typed them in).  I fixed the original post.

[GreySuits]

did you wire the bypass and in/out jacks as well? can we see pics of if you did, please?

Here is a pick of the bypass, I used the madbean 3PDT PCB:





Here is a link to the information on the PCB:
http://www.madbeanpedals.com/projects/_folders/Other/pdf/3PDT_2017.pdf

[GreySuits]

I found the problem!  The link between R6 and C3 had been severed (from me scratching it with a knife).  I soldered the 2 leads back together and the effect works now.

Thanks everyone for your help on this!

[ElectricDruid]

I found the problem!  The link between R6 and C3 had been severed (from me scratching it with a knife).  I soldered the 2 leads back together and the effect works now.

Thanks everyone for your help on this!

Well done!

That's the trouble with black solder mask. It's so dark you can't see where the tracks are underneath it. Green or red you can see through well enough to avoid the tracks.

[duck_arse]

excellent.