# Informant - no sound



## Allthumbs (Aug 11, 2019)

sadly my Informant build does not work.  I need an intro to going through the pedal with a multimeter.  Does anyone have a good link that will explain this and teach me how to find my problem?  something basic and straight forward for a noob?

Thanks


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## Nostradoomus (Aug 11, 2019)

Pictures of the build?


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## Allthumbs (Aug 13, 2019)

Nostradoomus said:


> Pictures of the build?



sorry for the holdup.  I'm waiting for a new 3PDT to swap it out.  I believe I shorted it with solder when attaching the breakout board.  If it turns out not the case I'll post some pics.  I can't find anything that looks odd but I need to learn to go through it with the MM.   I've been going on dumb luck


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## Nostradoomus (Aug 13, 2019)

That’s why I built a test rig! Less things to debug, especially 3pdt switches haha


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## Allthumbs (Aug 14, 2019)

Nostradoomus said:


> That’s why I built a test rig! Less things to debug, especially 3pdt switches haha


that's a great idea.  how do you connect the board to it?


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## zgrav (Aug 14, 2019)

did you find some sites that show you how to use your digital multimeter?  should be a few that come up with a search.  
for starters you can check out the guides here:  https://guitarpcb.com/forums/topic/pedal-building-guides-mandatory-reading/


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## Nostradoomus (Aug 14, 2019)

Allthumbs said:


> that's a great idea.  how do you connect the board to it?



I wired up an enclosure with all the usual off board wiring, then in place of the board wires I used cables with alligator clips attached to them. Wire a few flying leads off the board, clip em on and voila!


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## Jonathan (Aug 14, 2019)

Here's my favorite test rig, I recommend these every time this question comes up.  Changed everything for me:   https://tagboardeffects.blogspot.com/2014/09/test-box-20.html


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## Nostradoomus (Aug 14, 2019)

Yeah mine is basically that minus the probe and speaker terminals swapped with alligator clip cables. I also got the test rig PCB from JMK and it works wonders


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## Allthumbs (Aug 14, 2019)

zgrav said:


> did you find some sites that show you how to use your digital multimeter?  should be a few that come up with a search.
> for starters you can check out the guides here:  https://guitarpcb.com/forums/topic/pedal-building-guides-mandatory-reading/



I found some on operating the MM but none regarding the specifics of going through a circuit.  I'll check out the link. thanks.  I'm swamped with work lately so I'm neglecting my builds


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## Allthumbs (Aug 14, 2019)

Nostradoomus said:


> I wired up an enclosure with all the usual off board wiring, then in place of the board wires I used cables with alligator clips attached to them. Wire a few flying leads off the board, clip em on and voila!


nice.  must try


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## Jonathan (Aug 14, 2019)

Allthumbs said:


> I found some on operating the MM but none regarding the specifics of going through a circuit.  I'll check out the link. thanks.  I'm swamped with work lately so I'm neglecting my builds


I find that an audio probe is more useful than a multi meter. I definitely use it more often. You can follow the schematic and test each component and see if there's audio and find the point where it stops. Incidentally there's an audio probe built into the test rig I recommended (I promise Im not being paid to shill it, it's just awesome).


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## Allthumbs (Aug 20, 2019)

let me know if  this shot is useful to anyone.  If not I can disconnect a few wires and spread it out.  The switch is good, all the components appear to be right.  I did remove all but the 2 pins from the jacks as they were switching jacks.  All I can think of is I need to re-flow the solder everywhere.  
still not quite sure on how to use MM to test things.  I'll dive into it when I have some time in a few days.  either with an audio probe or current

I appreciate anyone calling out any obvious mistakes I;m not seeing.  Still novice but I've had a few successes in the last few months, this one surprised me for not working.


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## Nostradoomus (Aug 20, 2019)

Definitely reflow on your pot pads, looks like some of them are barely hanging in there.


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## Devoureddeth (Aug 21, 2019)

The 3pdt board probably has a bad connection the soldering there looks a little suspect. I always fill my lug to the board it is pretty standard in the industry just don't push too much solder.


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## Allthumbs (Aug 21, 2019)

yes, going to reflow everything this weekend.  Also, I've been using this really thin solder, .022" dia.  It's good for controlling the amount on the board for resistors and caps but not so great for larger pieces.  Also, I think my tip is too hot still, seems to liquefy the solder too fast allowing it to flow through the holes


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## Allthumbs (Aug 24, 2019)

sadly reflowing solder didn't fix it.  I need to go through it all step by step.  I'll make the audio probe shown in the vids.  thanks


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## Allthumbs (Sep 1, 2019)

my pot wires are to the right side of the board?


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## Robert (Sep 1, 2019)

Can you measure the voltage on Pin 4 and Pin 8 of each TL072?

Set your DMM to DC volts, touch the black lead to your enclosure, red lead to the point you want to measure.


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## Allthumbs (Sep 2, 2019)

if pins are numbered:
1 8
2 7
3 6
4 5

then 4 reads 0 and 8 reads 19.97

R1 has no current.

On the switch with 3PDT board, only SW has current when off.  every other point has none on or off.


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## Allthumbs (Aug 11, 2019)

sadly my Informant build does not work.  I need an intro to going through the pedal with a multimeter.  Does anyone have a good link that will explain this and teach me how to find my problem?  something basic and straight forward for a noob?

Thanks


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## Allthumbs (Sep 3, 2019)

also no current at r4, r5, c8, d1, d2

I'm not exactly sure what all this means yet.  I'll try the schematic and work my way through.  maybe something will make sense, not knowing how to read one?


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## Allthumbs (Sep 3, 2019)

also, gain pot has no current, the filter pot has a tiny amount .07v, the volume has about 10 on each leg.


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## Allthumbs (Sep 5, 2019)

would it be fruitless to start replacing these components because there is probably a perfectly good explanation as to why they are not getting current?  Would the audio probe lead me to the problem?   

if R1 has no current, then should C1 also have none?  I know, I should know this but I'm attempting to learn

thanks for any input


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## zgrav (Sep 5, 2019)

best use of your time troubleshooting is to get the schematic for your build and use your digital multimeter to make sure that the parts connect together the way they are laid out in the schematic.  if everything connects the way it should, then you check to make sure there are no "extra" connections to ground in the parts that carry the audio signal and the power.  when you find parts that should connect but do not, you figure out what the problem is and fix it (usually a bad connection to the board, which is why the first advice given is usually to check the connections on the board and touch up anything that looks questionable).


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## Allthumbs (Sep 5, 2019)

zgrav said:


> best use of your time troubleshooting is to get the schematic for your build and use your digital multimeter to make sure that the parts connect together the way they are laid out in the schematic.  if everything connects the way it should, then you check to make sure there are no "extra" connections to ground in the parts that carry the audio signal and the power.  when you find parts that should connect but do not, you figure out what the problem is and fix it (usually a bad connection to the board, which is why the first advice given is usually to check the connections on the board and touch up anything that looks questionable).



thank you.  I'm attempting to do that.  Right off the bat R1 has no current first component out of the gate.   next in line is C1 which does.  there is current until R4. 

hence my confusion


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## zgrav (Sep 5, 2019)

my suggestion is a bit different.  instead of checking to see if you have current or voltage, use the schematic to make sure the parts connect to each other as shown in the schematic.      so you see if the "IN" part on the pcb connects to R1 and C1.  then see if the other side of C1 connects to R2, then check to see if the other side of R2 connects to both R3 and pin 3 of IC1, etc etc etc      

if the schematic shows a connection between some parts and you cannot confirm they are connected, you have found at least one area where something needs to be identified and fixed.

you can print out the schematic and put check marks on the places that test OK and question marks on any areas that are not connecting like they should be.


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## Allthumbs (Sep 5, 2019)

please forgive my ignorance.  are you suggesting that I look and see a phisical connection from R1 to C1 such as shown on the schematic, and so on?  on the board?  is this to determine that there is no trace break or of there is a bridge somewhere?


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## zgrav (Sep 5, 2019)

use your DMM to check to see if the parts are connected that the schematic says are supposed to be connected.   You are doing that to go through all of the connections to look for something that is not connecting the way it is supposed to.

if you are not familiar with doing that you should watch some youtube videos that will show you how to do it.   use this link:


			how to use dmm to check connections in a circuit - Google Search


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## Allthumbs (Sep 5, 2019)

Thanks, I assumed that's what I was doing but I should watch the video
edit
haha, yes, definitely need to watch many more video, thanks again


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## Allthumbs (Nov 14, 2019)

I shelved this thing for a long time.  I just couldn't deal with the task of tracing the board and my earlier attempts didn't produce any real problems after sussing them out so I was stymied by my lack of knowledge.
I kept thinking about what I did wrong and I kept picturing those Switching jacks that I removed contacts from.  Did I remove the wrong contacts?

Yes I fucking did.  The pedal works great.

I learned a lot from the info everyone provided.

Thanks


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## zgrav (Nov 14, 2019)

Sometimes setting a board aside for a while and then coming back to it will give you insight on something you may have missed.  Glad you got it working.


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## Many__Of__Horror (Nov 14, 2019)

Allthumbs said:


> I shelved this thing for a long time.  I just couldn't deal with the task of tracing the board and my earlier attempts didn't produce any real problems after sussing them out so I was stymied by my lack of knowledge.
> I kept thinking about what I did wrong and I kept picturing those Switching jacks that I removed contacts from.  Did I remove the wrong contacts?
> 
> Yes I fucking did.  The pedal works great.
> ...


We always appreciate a follow up with a happy ending


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