im building the betty brown od, and came across a problem where pin 1 of ic2 doesnt produce any signal, as read on the oscilloscope. when pin 1 is disconnected from the pcb, the pedal functions excluding, what i assume, the ic2.1 section.
I have to raise this ongoing issue when Members ask for Help with an Issue with their Build.
I keep repeating this saying '' Pictures are worth a Thousand Words'' !!!
Please supply Pictures of PCB & ALL connections ( Footswitch, Input & Output Jacks, Power Jack ) to it along with a clear explanation of the Issue with your Build in the Troubleshooting Forum!
You will save a lot of Back & Forth guessing from the Help available to you if we can see the actual Build!
This will result in a quicker & less stressful environment!
Image 1 is the signal of pin 7 on ic2, the second image is pin 1 of ic2 and. which i infer to be infinite gain or just dc. i have already changed and audited all the components involved in ic2.
Sorry... your soldering does need a little work... one of your ic legs looks bridged to a resistor.... Could just be that flux is reflecting light.. you should probably clean the board well with 99% iso ....doesn't appear you have insulators on the back of your potentiometers either..
No bridging at the ic, i took out pin 1 to test whether rest of circuit was functional, which it was. also sceptical soldering near ic2.1 as a result of changing components. had tape behind pots but took it to make it easier to work with. any ideas. tried shorting pin 2&3 and still no output.
No bridging at the ic, i took out pin 1 to test whether rest of circuit was functional, which it was. also sceptical soldering near ic2.1 as a result of changing components. had tape behind pots but took it to make it easier to work with. any ideas. tried shorting pin 2&3 and still no output.
it's strong tape but okay, can you help regarding with the issue stated above. this back and forth will not help. regarding it it's either reading as infinite gain as according to how inverting op amps function or just reading dc. what is a possible solution apart from replacing as i have tried already.
it's strong tape but okay, can you help regarding with the issue stated above. this back and forth will not help. regarding it it's either reading as infinite gain as according to how inverting op amps function or just reading dc. what is a possible solution apart from replacing as i have tried already.
Did you try cleaning the flux off the board with Isopropyl alcohol? I would start with that and then reflow the solder on both sides of the board if that doesnt work.
still having the same issue after clean and re flow of both sides. pin 1/c9 output leg still reading dc or infinite gain. is there something fundamentally simple im not thinking of?
From what i can see on your pictures, some of your soldering joints look suspicious.
Some of the legs are bent on the pcb. That can cause shorts with nearby traces or soldering pads. Re-heat, bend them back to vertical position with the tip of your iron, and cut them if they are too long. Suck off the solder and redo the soldering if there is too much solder.
You noticed an issue on IC2 pin 1. This could be caused by some part connected to it. Check this aera, with your multimeter make sure there aren't any shorts, and that each part is connected to the next one as they should, following the schematics.
First you can fix your soldering pads. Then, you can follow the signal path with your multimeter on continuity mode, see if you find shorts or bad connections. You can also follow the signal path with an audioprobe and make sure the issue really appears at IC2, if you cant find anything suspicious at all, you should post some voltage readings as instructed in this debugging guide :
[DIY Fever] Audio Probe - very simple contraption that helps with debugging audio circuits
diy-fever.com
To follow the signal path, you look at the schematics and start by the quickest path from IN to OUT, the shortest line. Send a signal into the circuit, from a loop station, or any kind of signal going in. Probe some part here and there along this path. Once you find a spot where the signal stops, find the precise location where the signal stops, look closer to this section of the schematics and all the parts that are connected to that spot. Hunt for shorts or a bad connections with the multimeter, check parts values, etc.
