# Problem PCB Pauper



## coccoslash (Jun 4, 2020)

Hi everyone.
I have a problem on the Pauper. I think I burned the pads where the diodes are soldered (I did various tests changing from Ba283s to 4148s..and I did the damage). Practically the on/off/on selector no longer works. Acting on the switch, the pedal always remains only in the OD position (I think ... or maybe DIST).
Is there a way to bypass the PCB and attach the diodes directly to the switch? Or other solutions?

Thanks so much


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## Barry (Jun 4, 2020)

Probably going to need to see a picture of what's damaged


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## coccoslash (Jun 5, 2020)

here they are.
I ask you for information. How many degrees do you set the soldering iron for PCBs? (Celsius)?
Thanks


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## TheSin (Jun 7, 2020)

Im no expert, but judging by your pics, that pcb looks toasted. If it were me I’d salvage what I could off this, get me another pcb, and start over, that’s just me though....chalk it up to a learning experience.
I have one of those cheapie irons and I run mine on lowest setting, which is around 400 degrees F, and I turn it up when doing jacks and switches, also a little flux. Check out the “Basic workflow tips“ thread in general questions section. I’d also socket your diodes next time if you intend on experimenting....good luck and I hope you get it going.


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## Mcknib (Jun 7, 2020)

I always run mine at 390 to 400 degrees celcius for pcb work

It does also depend on which type of solder you use I personally use 60/40 leaded and never lead free, I just don't get on with it! but a lot of people seem to like it, with lead free I think you'd have to increase your temperature a wee bit

As far as I can see your switch looks ok, as in solder joints and the diodes look to be connected as below, so it'd just be a case of hard wiring your diodes as per the schematic the pads marked with the green dots are the ones that look damaged 2 on the top right and the 4 bottom pads so I think it would just be a case of connecting your diodes via small jumpers as shown

So basically put your diodes through the holes and solder small jumpers (red) where the damaged pads are (green) I'd do it on the solder side of the board and obviously watch to don't apply too much heat to your diodes you only want your iron on them for around 4 seconds or use a small croc clip as a heatsink


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## coccoslash (Jun 8, 2020)

Mcknib said:


> I always run mine at 390 to 400 degrees celcius for pcb work
> 
> It does also depend on which type of solder you use I personally use 60/40 leaded and never lead free, I just don't get on with it! but a lot of people seem to like it, with lead free I think you'd have to increase your temperature a wee bit
> 
> ...



Thanks a lot! Ok for the degrees: I use approximately 380C° (with 60/40 leaded).
I'll try to jumper the diodes following your scheme.
I'll let you know.


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## Mcknib (Jun 8, 2020)

It should work....but it was late! 

As you probably know you're simply bypassing the traces and connecting the components directly 

I'd perhaps test your diodes first with your meter make sure they're ok


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## coccoslash (Jun 8, 2020)

Mcknib said:


> It should work....but it was late!
> 
> As you probably know you're simply bypassing the traces and connecting the components directly
> 
> I'd perhaps test your diodes first with your meter make sure they're ok


Ok I made these mod, following your scheme (see attached photo).
Now I have UP position OK (should be OD or DIST mode?)..anyhow there's clipping.
MIDDLE position OK (Boost mode, it removes the diodes)
DOWN position: I've another Boost Mode ..so there's no clipping in down position.
What can I do?

thanks 
PS 
Diodes tested with meter. They are OK


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## Mcknib (Jun 8, 2020)

Perhaps those 2 pads aren't ok, try putting a link there, some of your solder joints are ball like and could be dry inside I'd reflow those


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## coccoslash (Jun 9, 2020)

Mcknib said:


> View attachment 4830
> 
> Perhaps those 2 pads aren't ok, try putting a link there, some of your solder joints are ball like and could be dry inside I'd reflow those


Ok did it, see photo. But seems nothing happens 
Thanks


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## Mcknib (Jun 9, 2020)

Check your switch has continuity in the down position, switched down the middle and top lugs should connect and beep

You've still got a few blobs of solder which could be dry inside I'd try to remove some but carefully I notice your dip switch and a coupla caps are melted a wee bit


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## Mcknib (Jun 9, 2020)

As somebody not to my musical taste, once said......

Now don't be sad coz 2 outta 3 ain't bad haha


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## coccoslash (Jun 9, 2020)

Mcknib said:


> Check your switch has continuity in the down position, switched down the middle and top lugs should connect and beep
> 
> You've still got a few blobs of solder which could be dry inside I'd try to remove some but carefully I notice your dip switch and a coupla caps are melted a wee bit


Yeah 2/3 is not so bad ahaha 
I check continuity: ok, switched down middle and top lugs are connected.
I also check the continuity of the wires and the diodes (following your scheme) and seem ok.
I'll try to remove the blobs of solder..


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## Mcknib (Jun 9, 2020)

When it's in the down position does the dip switch, any of the pots or maxing your guitar volume affect it i.e do you get more dirt

As far as I can work out Down would be overdrive mode


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## Mcknib (Jun 10, 2020)

Here's how the DPDT connects, confirmed by the main man, and after a lot of head scratching and looking at schems

You can continuity check your switch connections to make sure they're connected like this, any VREF point will do to check that lug, junction of R12 and 13, top of R2 etc


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## coccoslash (Jun 10, 2020)

Mcknib said:


> Here's how the DPDT connects, confirmed by the main man, and after a lot of head scratching and looking at schems
> 
> You can continuity check your switch connections to make sure they're connected like this, any VREF point will do to check that lug, junction of R12 and 13, top of R2 etc
> 
> View attachment 4866


This is very helpful.
Unfortunately, these two days, I've the painters at home and my laboratory is dismantled ?
Sorry but my English is not so good ( I'm Italian..)..
So, with the toggle up, I'd have the od and with the toggle down the distortion?
As soon as I can I'll test with multimeter the points.
Thanks a lot mate! ??


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## Mcknib (Jun 10, 2020)

I think so! I don't have the pcb and connecting virtual switches with a schem isn't my best skill!

Distortion you'd flip the switch down connecting the middle and top lugs like a proco rat hard clipping set up . 

Middle I think takes the diodes out of circuit for clean boost and flipping the switch up connects the middle and bottom lugs for a softer OD clipping arrangement in the op amp feedback loop more like a tubescreamer 

The way the switch connects can confuse, flip it up you'd expect the common middle and upper lugs to connect but no!

Anyway you can have a look here for a bit of info on the rat and ts clipping amps

https://www.electrosmash.com/tube-screamer-analysis

https://www.electrosmash.com/proco-rat


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## coccoslash (Jun 14, 2020)

Mcknib said:


> When it's in the down position does the dip switch, any of the pots or maxing your guitar volume affect it i.e do you get more dirt
> 
> As far as I can work out Down would be overdrive mode



Here I am   
The down position acts like the center posotion (boost): any pots affect the sound (also the dip switches).
Is like having (1x) OD mode and (2x) Boost mode
I also check the continuity, as you described, and it seems all ok


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## Mcknib (Jun 15, 2020)

So your switch continuity is good middle common lugs connect to top lugs and flipped the other way middle connects to bottom

Each lug connects to the components detailed e.g. top left to VREF, middle left to D3 cathode and D1 anode and so on

It sounds like D3 and 1 are not conducting 

Check that your switch poles don't have continuity specifically the 2 top ones 

When you checked your diodes what forward voltage reading did you get


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## coccoslash (Jun 16, 2020)

Mcknib said:


> So your switch continuity is good middle common lugs connect to top lugs and flipped the other way middle connects to bottom


Yes


> Each lug connects to the components detailed e.g. top left to VREF, middle left to D3 cathode and D1 anode and so on


Done..Ok


> It sounds like D3 and 1 are not conducting
> Check that your switch poles don't have continuity specifically the 2 top ones


Done, Ok


> When you checked your diodes what forward voltage reading did you get


D1= 114mv
D2= 125mv
D3= 147mv
D4= 109mv


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## coccoslash (Jun 4, 2020)

Hi everyone.
I have a problem on the Pauper. I think I burned the pads where the diodes are soldered (I did various tests changing from Ba283s to 4148s..and I did the damage). Practically the on/off/on selector no longer works. Acting on the switch, the pedal always remains only in the OD position (I think ... or maybe DIST).
Is there a way to bypass the PCB and attach the diodes directly to the switch? Or other solutions?

Thanks so much


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## Mcknib (Jun 16, 2020)

They look ok, datasheet says 100mv so given meter accuracy and test conditions in the datasheet they're ok

What's you're VREF voltage


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## coccoslash (Jun 16, 2020)

Mcknib said:


> They look ok, datasheet says 100mv so given meter accuracy and test conditions in the datasheet they're ok
> 
> What's you're VREF voltage



How can I measure it?


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## Mcknib (Jun 16, 2020)

Set your meter to 20 vdc black probe to ground red to the VREF switch lug


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## Mcknib (Jun 16, 2020)

The forward voltage for an MA856 is actually 1v in the datasheet, I can't read datasheets right!


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## coccoslash (Jun 16, 2020)

Mcknib said:


> The forward voltage for an MA856 is actually 1v in the datasheet, I can't read datasheets right!



I use 4148s

It measures 4,5v


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## Mcknib (Jun 16, 2020)

They should be around 0.7 forward voltage

Anyway spoke to Mr Ppcb again to double check those traces are correct pcb images are not always accurate  but they're confirmed ok

So the only thing I can think of is those diodes aren't conducting properly for some reason VREF should be half the power supply 

As he pointed out you are getting audio in that position just not distorted


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## coccoslash (Jun 16, 2020)

Mcknib said:


> They should be around 0.7 forward voltage
> 
> Anyway spoke to Mr Ppcb again to double check those traces are correct pcb images are not always accurate  but they're confirmed ok
> 
> ...



I mean, 4,5v is the VREF voltage.


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## Mcknib (Jun 16, 2020)

coccoslash said:


> I use 4148s
> 
> It measures 4,5v



That's correct you've definitely got gain turned up?


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## coccoslash (Jun 16, 2020)

Mcknib said:


> That's correct you've definitely got gain turned up?


I've always (2x) boost mode (middle and down)..I see no solutions


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## Mcknib (Jun 16, 2020)

There's always a solution! mind you it escapes me for the moment 

Look at your positives, you never trashed the pcb, you've hopefully learnt something, you had nothing on your SW, now got 2 and 3 will definitely be the magic number 

It'll be something simple and easily overlooked 

Lets see a picture of it now both sides 

I'll see if I can see anything when I finish work best actually do a bit...work that is!


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## coccoslash (Jun 16, 2020)

Mcknib said:


> There's always a solution! mind you it escapes me for the moment
> 
> Look at your positives, you never trashed the pcb, you've hopefully learnt something, you had nothing on your SW, now got 2 and 3 will definitely be the magic number
> 
> ...


Thanks Mate!   You're right..
I attach more photos


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## Mcknib (Jun 16, 2020)

Had a look you've still got solder joints that are like blobs of solder those could be dry inside using solder as a jumper will work but it's not advisable, change those for small jumpers like cut off component legs put a little solder on them and some on the part you're joining them to and it'll be easier to put them in place

Does D3 have a crack across it


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## coccoslash (Jun 16, 2020)

Mcknib said:


> Had a look you've still got solder joints that are like blobs of solder those could be dry inside using solder as a jumper will work but it's not advisable, change those for small jumpers like cut off component legs put a little solder on them and some on the part you're joining them to and it'll be easier to put them in place
> 
> Does D3 have a crack across it
> 
> View attachment 4986View attachment 4987



Ok thanks. I'll try cut off component legs.
D3 seems ok..but I can change it (I've several 4148)


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## coccoslash (Jun 17, 2020)

So .. I'm going to throw it out the window 
Blobs removed and I use component legs for the joints.
Changed all diodes (used BA283s..maybe I prefer 4148s ), changed switch with new one...nothing changed.
Still (1x) OD mode and (2x) Boost modes 
I am tempted to change the switch to an on/on type and close the issue (and use only 2 modes)


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## Mcknib (Jun 18, 2020)

Don't change anything till you know it's broken

If it's working ie you get audio through the switch the fault must lie elsewhere go over your build and visually check for cold solder joints and reflow any dull or blobby looking joints

It will be something simple a cold solder joint, bridge etc check R15,  R9 and C14 all have good joints and take the voltage at pin 7 IC1.2 which should be good if the other positions work

And to make 100% sure what working position it's in - od or distortion, when you've got it in that working position continuity check which switch lugs are connected and what components they connect to

The switch position it's in, in the schematic is distortion - out the op amp then down from the 1Ks through the diodes to VREF like a rat except 4 diodes so check everything from pin 7 down to VREF is all good

Perhaps we've been concentrating on the switch and diodes too much


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## coccoslash (Jun 18, 2020)

Mcknib said:


> Don't change anything till you know it's broken
> 
> If it's working ie you get audio through the switch the fault must lie elsewhere go over your build and visually check for cold solder joints and reflow any dull or blobby looking joints
> 
> ...



Thanks. Unfortunately I think I have permanently burned everything. Even the led. The pedal doesn't work anymore completely.
Thanks but I decided to throw the PCB away, buy a new pcb and do it again when I feel like it again.
I thank you for your support. I hope to hear from you.

Edit: Pauper is out of stock...great


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## Mcknib (Jun 18, 2020)

Never mind at least you learned a few things...hopefully!

It's a shame you removed the switch that in itself isn't easy to do

Although it's difficult when you're frustrated you've just got to stay calm and not remove anything until you know it's faulty

That's a shame you were almost there!

I suppose patience is a virtue............................That nobody wants!


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## zgrav (Jun 18, 2020)

when you order another board, order more than one kind of pedal you want to build and try to go ahead and order the parts for both boards.  it saves money on shipping costs, and it is easier to set a problem board aside to clear your head if you have another pedal you can start working on.   and when you order parts for a board like resistors, caps, jacks and switches, go ahead and order a few extra to start building an inventory.  no need to rush, but you will see savings on shipping and get a head start on future builds.


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