SOFTii Overdrive Defective PCB?

[FBC]

Hello everyone!

I bought a Softii Overdrive Kit (PedalPCB) and after assembled I noticed that the Gain pot did nothing. It looked like it was always maxed out. I tested the pot and it looked like it was the flaw. When I had it all the way down (minimum gain), it would short in all the legs of the pot (I tested with a multimeter). When the pot was all the way up (maximum gain) it was only shorting in 1 pair of legs.
Since I wasn't going to use it in my current project and was expecting to do another order I waited and bought a new potentiometer. I changed the pot (tested it before putting in the pedal and it was fine (only shorted 1 pair in maximum and minimum)) and nothing changed. I return to test it (while it was soldered on the PCB) and it starts to happen what happened with the original pot (shorting in all legs).
I tested the original pot after replacing it (without being soldered to the PCB) and it is fine (only 1 pair in each time).

After looking at the board I noticed something: In the PCB, one of the legs of Q1 is not connected where it should be.
Since it's a bit hard to explain I'll attach some pictures:




It looks like its missing on the board:


After seeing that problem, I made the connection myself. The pot is working now, but not fully. It changes the gain, but it's reducing clockwise which I think it's not supposed. Also, when in the stones mode (blue LED), when the gains is low it almost makes no sound... Video after fix: https://drive.google.com/file/d/1d1oCzM580ToH3mQ9GF_3RlHnC6sqrMiR/view?usp=sharing

It still doesn't seem right, and since I saw that defect in the Q1 I believe that maybe the board has other problems...

The only change I did was to use a footswitch instead of the original switch that comes with the pedal so I can change the mode while playing, but I don't believe that it affects the pedal in the way I'm saying...

After sending this information to musikding, it was passed to PedalPCB. The reply was that the connection that is missing is on the other side of the pcb and that I should contact PedalPCB directly (hence this post, I did not see a direct contact).

However, after being told that the connection is on the other side of the board I checked with a multimeter and it looks like there is no contact: https://drive.google.com/file/d/1LrhXNEvzhEZbHx-w81TK3P8gA_4xoikk/view?usp=sharing

This is everything I checked, any idea of what is going on? Since that in this last test it lookes like it doesn't make contact I still believe that something is wrong with the board.

Thanks in advance for reading.

Best Regards,
Fábio

 

[ReinoutVrijhoef]

I don't have an answer for you, and I hope you can fix this any time soon. I just wanted to make a compliment on a well written and explained problem, kudos! For completeness sake, could you post a picture of the back of the board? Leg 3 of Q1 should also be connected to R2 and R22, have you checked those connections, and maybe the other side of R19?

 

[cdwillis]

Can you not turn the board over and see if that missing trace is on the bottom of the pcb? I would assume it's missing given that you didn't get any continuity, but it could be a cold solder joint on the bottom.

 

[Robert]

That trace is on the bottom side of the PCB, post a pic of the back.

I'm certainly not saying it's impossible, but having multiple fabrication errors in a single PCB is highly unlikely.

 

[Laundryroom David]

Have you conducted a close visual inspection of both sides of the board? Confirmed the pinout of the transistors? Confirmed all component values are correct? Reflowed your solder joints? (I see some that look cold). Checked transistor voltages? See where I’m going with this?

Don’t get me wrong. PCB errors happen, but it’s really rare. People come on here all the time blaming the board and then like 20 posts in it turns out to be something that could have been caught with proper troubleshooting at the outset. 99% of the time, the board fault turns out to be a builder’s error (myself included).

 

[carlinb17]

just jump it...

 

[derevaun]

Just to be clear, what's going on with the crossed legs of Q1?

 

[PJS]

Looking at what Robert has posted it looks as if that trace goes to the other end of that resistor, not the close one. That will be why there is no connection between the transistor and the closest leg of the resistor - there is not supposed to be.

 

[spi]

The diagram you posted of the traces doesn't match the current picture on the site. Are there multiple revisions of this PCB (the build doc does say it was revised last August)? Could it be the wiring you're expecting from the picture doesn't match the version of PCB you have?

 

[FBC]

Ok, a little update.
Thank you all for the replies and sorry for my delay, I do not have much free time to dedicate to the pedal these last days.
So, as some of you recommended I checked the connection to the other leg of the resistor and they are connected. Probably my board is a different version.
For those who mentioned that it's highly uncommon to have a defective PCB don't get me wrong, I completely agree with you, but sometimes when I find something that might be a mistake it's hard to look for and find other problems.
So, now I know that the problem is not the board and I can focus on finding the problem.

I don't have an answer for you, and I hope you can fix this any time soon. I just wanted to make a compliment on a well written and explained problem, kudos! For completeness sake, could you post a picture of the back of the board? Leg 3 of Q1 should also be connected to R2 and R22, have you checked those connections, and maybe the other side of R19?

Thank you!

Have you conducted a close visual inspection of both sides of the board? Confirmed the pinout of the transistors? Confirmed all component values are correct? Reflowed your solder joints? (I see some that look cold). Checked transistor voltages? See where I’m going with this?

Don’t get me wrong. PCB errors happen, but it’s really rare. People come on here all the time blaming the board and then like 20 posts in it turns out to be something that could have been caught with proper troubleshooting at the outset. 99% of the time, the board fault turns out to be a builder’s error (myself included).

That will be the next step, I believe the pinouts are ok. I'll check the transistor voltages (that will be a first for me, I would never think of that, thank you.)

Just to be clear, what's going on with the crossed legs of Q1?

I don't understand, what do you mean? I the legs are in order, I didn't cross them (like, leg 1, 2 and 3 are on the holes in that sequence). Maybe its because of the angle of the picture?