# SOLVED: Brown Betty Issue. No sound.



## Loxton (May 18, 2022)

Hi, I'm having an issue with no audio when engaged. 
The volume pot and trim pot has a scratchy audio when turned.
Led4 lights up when the trim pot is fully counter-clockwise.
Led3 lights up when turned 1/4 turn - fully clockwise.
I have audio up to IC2 pin 2 and 7 then nothing after that. 
R14 was removed and retested great but no audio on the left side of it. No audio at C9.
Replaced IC2 with same results.
I replaced the trim pot with the same results

I'll re clean the board and get some more info and pictures.

See IC readings in attachment


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## music6000 (May 18, 2022)

Do a Continuity check on Matching Circles, put the Probe on the trimmer  of 2 & 3 legs to make sure they are linked
R14 to trimmer leg 1


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## Loxton (May 18, 2022)




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## Chuck D. Bones (May 18, 2022)

We still need to make sure there is no "extra" connection to IC2-2.

Power off.  Remove IC2, set TRIM to minimum (full CCW) and then measure the resistance from pin 1 to pin 2 on IC2's socket.

I see cold solder joints on the BASS & GAIN pots.  Pin 1 of the TRIM is also suspect.

First, INSPECT everything.  Then reflow the suspect joints.


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## Loxton (May 18, 2022)

music6000 said:


> Do a Continuity check on Matching Circles, put the Probe on the trimmer of 2 & 3 legs to make sure they are linked
> R14 to trimmer leg 1


Tested good.


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## Loxton (May 18, 2022)

Chuck D. Bones said:


> Power off. Remove IC2, set TRIM to minimum (full CCW) and then measure the resistance from pin 1 to pin 2 on IC2's socket.


9.94k ohms. From memory that was the measurement of R14


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## Chuck D. Bones (May 18, 2022)

Turn the trimmer full CW and measure again.  Should be around 110K.


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## Loxton (May 18, 2022)

Chuck D. Bones said:


> Turn the trimmer full CW and measure again. Should be around 110K.


107.1k ohms


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## Chuck D. Bones (May 18, 2022)

That's all good.  It appears we do not have any missing connections to IC2.1, but we might have an extra connection to pin 2.  Carefully inspect around IC2, R13, R14 & the TRIM pot.  Look for conductive debris trapped under IC2's socket.


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## music6000 (May 18, 2022)

Chuck D. Bones said:


> That's all good.  It appears we do not have any missing connections to IC2.1, but we might have an extra connection to pin 2.  Carefully inspect around IC2, R13, R14 & the TRIM pot.  Look for conductive debris trapped under IC2's socket.


Yep, pull IC2 & do Continuity test between Pins 1 & 2, 2 & 3, 3 & 4, 5 & 6, 6 & 7, 7 & 8


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## Loxton (May 18, 2022)

Chuck D. Bones said:


> Carefully inspect around IC2, R13, R14 & the TRIM pot. Look for conductive debris trapped under IC2's socket.


I spent a good time looking and can't see anything out of the ordinary


music6000 said:


> pull IC2 & do Continuity test between Pins 1 & 2, 2 & 3, 3 & 4, 5 & 6, 6 & 7, 7 & 8


all good . only continuity between 3 and 5 (VDD)


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## Chuck D. Bones (May 18, 2022)

I don't know what else to tell you.  Something's not right and everywhere we look, you says it's good.


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## Loxton (May 18, 2022)

I have continuity between ground and R14/C9 and trim (1)


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## Chuck D. Bones (May 18, 2022)

BINGO!  Now we need to find what is making that connection to GND.

Look for solder splashes around the R14 & C9 pads.


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## Loxton (May 18, 2022)

Continuity to ground here.


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## music6000 (May 18, 2022)

Loxton said:


> I have continuity between ground and R14/C9 and trim (1)


This area has me curious ????


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## Chuck D. Bones (May 18, 2022)

If you can't see anything around R14 & C9, then you'll have to remove the trimmer to see if the short is hidden underneath.  Exhaust all other possibilities before removing the trimmer.  Do you have a spare in case the trimmer does not survive the removal process?


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## Chuck D. Bones (May 18, 2022)

music6000 said:


> This area has me curious ????
> 
> View attachment 26438


I can't tell if there is a problem or not from that pic.


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## Loxton (May 18, 2022)

I had already removed the trim pot, R14 and C9, inspected and replaced them before I started asking for help.  I'll remove them again, do some digging and report back later. Thanks a bunch for all your help.


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## music6000 (May 18, 2022)

I'm with Chuck on this Trimmer!
This seems to be outside the Perimeter:


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## Loxton (May 18, 2022)

Hi, I'm having an issue with no audio when engaged. 
The volume pot and trim pot has a scratchy audio when turned.
Led4 lights up when the trim pot is fully counter-clockwise.
Led3 lights up when turned 1/4 turn - fully clockwise.
I have audio up to IC2 pin 2 and 7 then nothing after that. 
R14 was removed and retested great but no audio on the left side of it. No audio at C9.
Replaced IC2 with same results.
I replaced the trim pot with the same results

I'll re clean the board and get some more info and pictures.

See IC readings in attachment


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## Chuck D. Bones (May 18, 2022)

That looks like a board layout error.  Square pads should have a square clearance area around the pad.  Oops.


Loxton said:


> I had already removed the trim pot, R14 and C9, inspected and replaced them before I started asking for help.  I'll remove them again, do some digging and report back later. Thanks a bunch for all your help.


The only way you're going to fix this board is with a knife.  You have to cut away the ground plane around the corners of the square pad on both sides.  PedalPCB quality is normally excellent, but now and then shit happens.  I'm sure Robert will make it right.


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## music6000 (May 18, 2022)

Loxton said:


> I had already removed the trim pot, R14 and C9, inspected and replaced them before I started asking for help.  I'll remove them again, do some digging and report back later. Thanks a bunch for all your help.


Once you remove them, Check for continuity on the individual Pads & GND on the problem areas!


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## music6000 (May 18, 2022)

Chuck D. Bones said:


> That looks like a board layout error.  Square pads should have a square clearance area around the pad.  Oops.
> 
> The only way you're going to fix this board is with a knife.  You have to cut away the ground plane around the corners of the square pad on both sides.  PedalPCB quality is normally excellent, but now and then shit happens.  I'm sure Robert will make it right.


It can be fix by drilling Trim 1 Pad larger & running a separate Jumper from Trimmer 1 Leg to C9/R14  ???? if that is the Issue


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## Loxton (May 18, 2022)

Fixed! sorta. You guys were on the money. Removed trim R14 and C9. Still continuity to ground, so I Macgyvered it.
We have sound and everything seems to be working properly.


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## Chuck D. Bones (May 19, 2022)

Yeah, that'll work too.


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## Loxton (May 19, 2022)

Chuck D. Bones said:


> You have to cut away the ground plane around the corners of the square pad on both sides.


Solved. I carefully cut away the ground on all 4 corners on both sides, careful not to cut the trace to R14/C9. Had to check a few times with a multimeter. Then I made sure I didn't add to much solder, where it would flow into the ground section.
Thanks all for your help.


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## Robert (May 19, 2022)

That is _very_ unusual, I'll pull some boards today and see if more have this same issue.

The solder mask/ground pour clearance is designed into the component footprint so I'm puzzled how such a thing could have happened unless it's a fabrication error (also not very common).

The layout hasn't been changed in years, when did you order that PCB? 
Nevermind, I see it hasn't been that long at all.

Let me look into this today and see what's going on.  I should still have this same batch.


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