Noob feeling like an idiot - could use some assistance...

Started by Grendel2000, June 06, 2020, 06:22:21 PM

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antonis

"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

Grendel2000


jfrabat

Continuity in the board will not tell you anything...  do not worry about that.
I build.  I fix.  I fix again.  And again.  And yet again.  (sometimes again once more).  Then I have something that works! (Most of the time!).

Grendel2000

Quote from: jfrabat on July 19, 2020, 06:58:01 PM
Continuity in the board will not tell you anything...  do not worry about that.

I believe you, but wow that seems counterintuitive?  Is there an easy explanation as to why?

jfrabat

Quote from: Grendel2000 on July 19, 2020, 07:06:28 PM
Quote from: jfrabat on July 19, 2020, 06:58:01 PM
Continuity in the board will not tell you anything...  do not worry about that.

I believe you, but wow that seems counterintuitive?  Is there an easy explanation as to why?

Continuity typically measures if there is low resistance (which there should be in, say, a wire connection).  Typically, the resistance in a conductor will be less than 100 Ohm.  Introduce a resistor in the middle, say 1K, and now your continuity test will fail.

But do a simple experiment to verify this; do a continuity test of a resistor.  Put the MM on continuity, and touch the leads to either end of a resistor (again, say, 1K or higher).  It will not beep...
I build.  I fix.  I fix again.  And again.  And yet again.  (sometimes again once more).  Then I have something that works! (Most of the time!).

Grendel2000

Quote from: jfrabat on July 19, 2020, 10:19:36 PM
Quote from: Grendel2000 on July 19, 2020, 07:06:28 PM
Quote from: jfrabat on July 19, 2020, 06:58:01 PM
Continuity in the board will not tell you anything...  do not worry about that.

I believe you, but wow that seems counterintuitive?  Is there an easy explanation as to why?

Continuity typically measures if there is low resistance (which there should be in, say, a wire connection).  Typically, the resistance in a conductor will be less than 100 Ohm.  Introduce a resistor in the middle, say 1K, and now your continuity test will fail.

But do a simple experiment to verify this; do a continuity test of a resistor.  Put the MM on continuity, and touch the leads to either end of a resistor (again, say, 1K or higher).  It will not beep...

Ok, I get that, but if it DOES beep between two points, doesn't that imply that the connection everywhere between is ok?

jfrabat

Quote from: Grendel2000 on July 19, 2020, 10:24:51 PM
Ok, I get that, but if it DOES beep between two points, doesn't that imply that the connection everywhere between is ok?

Not necessarily...  You could have a short that makes the signal bypass a resistor, cap or transistor, and that could be the issue why the pedal is not working.
I build.  I fix.  I fix again.  And again.  And yet again.  (sometimes again once more).  Then I have something that works! (Most of the time!).

Grendel2000

Quote from: jfrabat on July 19, 2020, 10:34:16 PM
Quote from: Grendel2000 on July 19, 2020, 10:24:51 PM
Ok, I get that, but if it DOES beep between two points, doesn't that imply that the connection everywhere between is ok?

Not necessarily...  You could have a short that makes the signal bypass a resistor, cap or transistor, and that could be the issue why the pedal is not working.

Interesting!  What would normally cause a short like that?  Stray solder joining two traces maybe?

jfrabat

Quote from: Grendel2000 on July 19, 2020, 10:40:39 PM
Interesting!  What would normally cause a short like that?  Stray solder joining two traces maybe?

That is the most common cause, yes, a solder bridge.
I build.  I fix.  I fix again.  And again.  And yet again.  (sometimes again once more).  Then I have something that works! (Most of the time!).

Grendel2000

So I'm not sure where to go from here.

As I said earlier, using the testing tool I get a signal at the input jack and at the lower left lug of the foot switch but I get NO signal at the leftmost middle lug on the foot switch (green wire) in either position of the foot switch and I get NO signal at either lug on the Bias (R7) trim pot.

What should I check?

ElectricDruid

Quote from: Grendel2000 on July 20, 2020, 08:24:18 AM
I get a signal at the input jack and at the lower left lug of the foot switch
Good start! So signal gets in through the jack and gets to the foot switch.

Quote
but I get NO signal at the leftmost middle lug on the foot switch (green wire) in either position of the foot switch
This is crucial, since this takes the signal to the board. You'll only hear the signal at the green wire in one position of the foot switch not the other. On your photo, it looks like there's a bad joint on the foot switch with that green wire.

Are you using lead-free solder? It looks very dry and not shiny. Your iron is definitely still causing problems.

Quote
and I get NO signal at either lug on the Bias (R7) trim pot.
No, you won't, not until you've got signal going down that green wire.

Grendel2000

Quote from: ElectricDruid on July 20, 2020, 09:30:20 AM
Quote from: Grendel2000 on July 20, 2020, 08:24:18 AM
I get a signal at the input jack and at the lower left lug of the foot switch
Good start! So signal gets in through the jack and gets to the foot switch.

Quote
but I get NO signal at the leftmost middle lug on the foot switch (green wire) in either position of the foot switch
This is crucial, since this takes the signal to the board. You'll only hear the signal at the green wire in one position of the foot switch not the other. On your photo, it looks like there's a bad joint on the foot switch with that green wire.

Are you using lead-free solder? It looks very dry and not shiny. Your iron is definitely still causing problems.

Quote
and I get NO signal at either lug on the Bias (R7) trim pot.
No, you won't, not until you've got signal going down that green wire.

I had issues with the iron and tips getting rough.  I got a bit better educated on proper use and care over the course of this thread and have bought some tip tinner which has helped a TON.

I'll re-solder that switch lug and see what happens.

Thanks!

Phend

Grendel2000, I have read this thread, but maybe missed this, the foot switch can be switched to "clean ", meaning no effect just like the guitar being plugged directly into the amp.  Are you saying that you don't even get this clean sound. The circuit shows the path, simple.  I suspect that the input and output jacks ground lugs are not connected together. Usually this is done thru the metal of the box.
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Do you know what you're doing?

Grendel2000

Quote from: Phend on July 20, 2020, 09:46:57 AM
Grendel2000, I have read this thread, but maybe missed this, the foot switch can be switched to "clean ", meaning no effect just like the guitar being plugged directly into the amp.  Are you saying that you don't even get this clean sound. The circuit shows the path, simple.  I suspect that the input and output jacks ground lugs are not connected together. Usually this is done thru the metal of the box.

How would I check if the input and output ground lugs are connected?

ALSO:
I think I've identified an issue: I no longer get continuity between the lower left lug and middle left lug on the foot switch in either switch position.  I assume this means I've damaged the switch which would explain the signal stopping at the middle-left lug...

I've ordered a 2 pack of Kaish 3PDT switches that will hopefully be here Wednesday.  I guess I'll re-wire the foot switch then and see what happens...

duck_arse

QuoteHow would I check if the input and output ground lugs are connected?

continuity. you want a continous path between something nominated as ground [0V/earth/COMMON] and ANY OTHER POINT nominated as ground [0V/earth/common]. so set your meter to continuity [or low ohms range, or ohms if autoranging meter] and one probe to one jack sleeve and the other probe to the other jack sleeve.
" I will say no more "

jfrabat

In the meantime, if you want to test the board, you can wire the input and output cables directly to the jacks.  You will not be able to turn off the pedal, but at least you can try it!
I build.  I fix.  I fix again.  And again.  And yet again.  (sometimes again once more).  Then I have something that works! (Most of the time!).

11-90-an

Quote from: jfrabat on July 20, 2020, 10:44:42 AM
In the meantime, if you want to test the board, you can wire the input and output cables directly to the jacks.  You will not be able to turn off the pedal, but at least you can try it!
Just use alligator jacks (but not too long as to cause noise) if you don't want to break out your soldering iron again... :icon_biggrin:
flip flop flip flop flip

amptramp

Standard 3PDT switches are very susceptible to soldering damage.  If any of the terminals appear to have shifted, they may not be making contact.  I have repaired a wah pedal before that had that problem from the factory.

Grendel2000

Quote from: amptramp on July 21, 2020, 07:53:09 AM
Standard 3PDT switches are very susceptible to soldering damage.  If any of the terminals appear to have shifted, they may not be making contact.  I have repaired a wah pedal before that had that problem from the factory.

So is there a technique or trick that's best for getting the lugs soldered quickly to avoid damage?

bluebunny

Quote from: Grendel2000 on July 21, 2020, 03:31:29 PM
So is there a technique or trick that's best for getting the lugs soldered quickly to avoid damage?

Have a hot soldering iron.  It may sound counter-intuitive (since you don't want to burn anything), but it means everything heats up quickly so you can be in and out in a second or two.  This is true of all solder joints, not just switches.  If you're spending ages anywhere waiting for the solder to flow, your iron isn't hot enough.

It's worth practising on some scrap board with some spent components.  Perfect your in-and-out technique.   :icon_cool:
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Ohm's Law - much like Coles Law, but with less cabbage...