# Lemon Rockerverb- no sound when engaged



## megatrav

I've been working on this build from guitar pcb mania. 
I have bypassed sound. No sound when engaged but I do have an LED. 
I took some shots of the board and I can't spot any bad connections so I think I might have the switch Ground and Control backwards. The PCB only says CNTRL.
I haven't tried swapping them yet but I wanted to post here to see if anyone might catch something else I may have done wrong. 









Thanks!


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## BuddytheReow

is c3 supposed to be missing?


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## megatrav

BuddytheReow said:


> is c3 supposed to be missing?


Yes, it is
Here is the build doc:
Lemon Rockerverb


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## megatrav

One other thing, is was able to bias the jfets and they're all sitting right around 4.5v. So signal is getting to them at least


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## carlinb17

what are the 0/1 and 1/1 eyes for? they appear to be referenced in the schematic however there is nothing in documentations for them.


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## megatrav

carlinb17 said:


> what are the 0/1 and 1/1 eyes for? they appear to be referenced in the schematic however there is nothing in documentations for them.


I actually have no idea! maybe I should send them a message


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## temol

megatrav said:


> One other thing, is was able to bias the jfets and they're all sitting right around 4.5v. So signal is getting to them at least



Drain voltage is one thing, signal is another thing. You can have perfectly biased transistors and no sound at all. 
Trace the signal with an audio probe.


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## megatrav

temol said:


> Drain voltage is one thing, signal is another thing. You can have perfectly biased transistors and no sound at all.
> Trace the signal with an audio probe.


I really need to get around to making one of those. I was hoping someone would reveal something silly and obvious that I missed.


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## zgrav

it would be a good idea to put something on the two bare pot shells that are mounted above the PCB.


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## BuddytheReow

An audio pot is stupid simple to make if you've got alligator clips.
This is what it would look like. Drew it real quick with TinyCAD







The jack you use doesn't really matter as long as you can solder 2 wires to it: ground and the actual signal (marked tip). That goes to a capacitor. The capacitor should be roughly 100n and I used a box film one. It's purpose is to filter our all unwanted DC in the signal (you guitar sends AC signal). The other unused lead of the capacitor is your audio probe or you can solder a wire to that to make it a bit easier for testing.


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## megatrav

zgrav said:


> it would be a good idea to put something on the two bare pot shells that are mounted above the PCB.


Yes, I had some sticky pads on the bottom. I removed them so that I could take pictures of the under side of the board


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## megatrav

BuddytheReow said:


> An audio pot is stupid simple to make if you've got alligator clips.
> This is what it would look like. Drew it real quick with TinyCAD
> 
> 
> 
> 
> 
> 
> The jack you use doesn't really matter as long as you can solder 2 wires to it: ground and the actual signal (marked tip). That goes to a capacitor. The capacitor should be roughly 100n and I used a box film one. It's purpose is to filter our all unwanted DC in the signal (you guitar sends AC signal). The other unused lead of the capacitor is your audio probe or you can solder a wire to that to make it a bit easier for testing.


Thanks for the tip. Right now I don't have any gator clips or spare parts to make a probe, but that will be something I do in the future.


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## megatrav

Guitarpcbmania replied and said the 0/1 and 1/1 pads were originally added for modding, but they're useless and should be ignored.
I am going to try touching up all my joints and maybe swap the CTRL and Ground wires just to see if maybe it was something silly like that


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## megatrav

As it turns out, my efforts did not pay off. 
Should I test the jfets?


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## Feral Feline

C10 is backwards.

I'd also recommend trimming the teats more and then reflow the solder — check for micro solder bridges, a lot of your pads look as though on the verge of being bridged either by solder or by leaning towers of teats.


I need to build mine up, but then the same could be said for a lot of PCBs I have...


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## megatrav

Feral Feline said:


> C10 is backwards.
> 
> I'd also recommend trimming the teats more and then reflow the solder — check for micro solder bridges, a lot of your pads look as though on the verge of being bridged either by solder or by leaning towers of teats.
> 
> 
> I need to build mine up, but then the same could be said for a lot of PCBs I have...


Big thanks on C10. Since I uploaded the photo, I did reflow myself solder and check for any bridges. I will recheck and swap c10. Thanks for the assist!


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## megatrav

Flipped c10 and went over any long leads and checked for solder bridges. 
No luck.


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## Feral Feline

megatrav said:


> Flipped c10 and went over any long leads and checked for solder bridges.
> No luck.


I've got the old build doc, which showed C10 oriented with + north; but...
according to the build doc you linked to, you had C10 the correct way round in the first place — sorry to have misinformed you.

Can you repost new pics after touching up the solder?


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## megatrav

Feral Feline said:


> I've got the old build doc, which showed C10 oriented with + north; but...
> according to the build doc you linked to, you had C10 the correct way round in the first place — sorry to have misinformed you.
> 
> Can you repost new pics after touching up the solder?


No worries. I removed the cap and put it back in and later realized it was in the correct way all along haha. 

I did try to clean up my ends. I do need to scrub the board as it's gotten a little messy from touching up the pads. Here are some pics I just took.


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## carlinb17

if you have an old guitar cable, a little bit of hookup wire and a .1 uf capacitor somewhere I would recommend making an audio probe.


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## megatrav

I've been working on this build from guitar pcb mania. 
I have bypassed sound. No sound when engaged but I do have an LED. 
I took some shots of the board and I can't spot any bad connections so I think I might have the switch Ground and Control backwards. The PCB only says CNTRL.
I haven't tried swapping them yet but I wanted to post here to see if anyone might catch something else I may have done wrong. 









Thanks!


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## BuddytheReow

Are those 2 ground wires coming out of the board? Scratching my head why....


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## megatrav

carlinb17 said:


> if you have an old guitar cable, a little bit of hookup wire and a .1 uf capacitor somewhere I would recommend making an audio probe.


I may have to go see about getting some gator clips and making one


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## megatrav

BuddytheReow said:


> Are those 2 ground wires coming out of the board? Scratching my head why....


If you're referring to the top of the board the 3 ground wires are for the in/out jacks and dc jack


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## music6000

megatrav said:


> If you're referring to the top of the board the 3 ground wires are for the in/out jacks and dc jack
> View attachment 16585


Can you Confirm you have Continuity on the matching Coloured Circles on the 4 J201's pads as pictured :


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## megatrav

music6000 said:


> Can you Confirm you have Continuity on the matching Coloured Circles on the 4 J201's pads as pictured :
> 
> View attachment 16586


Q4 is good to go. I actually performed the same test on all the Jfets and Q2 blue doesn't appear to have continuity.


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## BuddytheReow

megatrav said:


> If you're referring to the top of the board the 3 ground wires are for the in/out jacks and dc jack


I was referring to the footswitch


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## megatrav

BuddytheReow said:


> I was referring to the footswitch
> View attachment 16588


I'm not sure what you mean? 
Would you be able to edit the pic?


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## BuddytheReow

OP says Ground and Control. Those 2 wires. What is the control for?


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## music6000

BuddytheReow said:


> OP says Ground and Control. Those 2 wires. What is the control for?


Control is SW


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## music6000

megatrav said:


> Q4 is good to go. I actually performed the same test on all the Jfets and Q2 blue doesn't appear to have continuity.


Use a piece of Resistor lead & Solder between  the 2 pads in blue on Q2 board, It maybe your issue!
Sometimes flux can give a false result!


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## music6000

megatrav said:


> Q4 is good to go. I actually performed the same test on all the Jfets and Q2 blue doesn't appear to have continuity.


I actually listed all 4 J201's needed testing in my original message, not just Q4 lol !


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## zgrav

asking the obvious question for the symptom you described (sound in bypass, but not when engaged)  -- are you sure you have the in and out jacks plugged in correctly?


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## megatrav

zgrav said:


> asking the obvious question for the symptom you described (sound in bypass, but not when engaged)  -- are you sure you have the in and out jacks plugged in correctly?


I believe so since I am able to get sound from my guitar when bypassed


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## BuddytheReow

megatrav said:


> I believe so since I am able to get sound from my guitar when bypassed


He's asking because if you've got your in out jacks wired backwards then bypass will work but not when engaged


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## music6000

megatrav said:


> I believe so since I am able to get sound from my guitar when bypassed


Just confirming, Your guitar lead is plugged into the Input jack of the Pedal & Output Jack of pedal is going to Amp.
I have accidently plugged them in the wrong way more than once when the Pedal or Circuit is upside down on the Floor !!!

Have you fixed the Continuity issue with Q2 Blue Pads?


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## megatrav

music6000 said:


> Just confirming, Your guitar lead is plugged into the Input jack of the Pedal & Output Jack of pedal is going to Amp.
> I have accidently plugged them in the wrong way more than once when the Pedal or Circuit is upside down on the Floor !!!
> 
> Have you fixed the Continuity issue with Q2 Blue Pads?


I did. All the jfets now have continuity. Unfortunately I still don't have any sound
when the pedal is engaged.


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## music6000

megatrav said:


> I did. All the jfets now have continuity. Unfortunately I still don't have any sound
> when the pedal is engaged.


Confirm that the guitar lead is plugged into the INPUT jack of the Pedal & Pedal OUTPUT jack is going to the Amp :


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## megatrav

music6000 said:


> Confirm that the guitar lead is plugged into the INPUT jack of the Pedal & Pedal OUTPUT jack is going to the Amp :
> 
> View attachment 16612


Yessir that is how I have it connected. I actually tried the other way too just to make sure.
When the pedal is engaged and connected the correct way there is a hum.


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## music6000

megatrav said:


> Yessir that is how I have it connected. I actually tried the other way too just to make sure.
> When the pedal is engaged and connected the correct way there is a hum.


Why does Q2 SMD look different to the other 3, Are they all the same Manufacturer?
Where did you purchase these?


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## temol

audio probe.. audio probe.. audio probe... au....


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## megatrav

I've been working on this build from guitar pcb mania. 
I have bypassed sound. No sound when engaged but I do have an LED. 
I took some shots of the board and I can't spot any bad connections so I think I might have the switch Ground and Control backwards. The PCB only says CNTRL.
I haven't tried swapping them yet but I wanted to post here to see if anyone might catch something else I may have done wrong. 









Thanks!


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## megatrav

music6000 said:


> Why does Q2 SMD look different to the other 3, Are they all the same Manufacturer?
> Where did you purchase these?


I got them all from Mouser
MMBFJ201


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## music6000

megatrav said:


> I got them all from Mouser
> MMBFJ201


What value capacitor do you have at C6 -100pF ?
It's different to C8 & C11 which are also 100pF ?


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## megatrav

I will 


music6000 said:


> What value capacitor do you have at C6 -100pF ?
> It's different to C8 & C11 which are also 100pF ?


I will have to take some readings later this weekend. I am pretty sure that c6 is 100pf but I am wondering if I put the wrong values at c8 and c11


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## megatrav

music6000 said:


> What value capacitor do you have at C6 -100pF ?
> It's different to C8 & C11 which are also 100pF ?


Those are also 100pf. They are just a different kind of ceramic capacitor. The cheaper ones from Tayda. 

An audio probe does sound like a good solution. 
Since I am hearing a hum when it is engaged would it be reasonable to think something is shorting to ground?


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## Feral Feline

+1 to audio probing it, as others have suggested.

The Diode pads and Preamp #1 still look suspect.


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## music6000

megatrav said:


> Those are also 100pf. They are just a different kind of ceramic capacitor. The cheaper ones from Tayda.
> 
> An audio probe does sound like a good solution.
> Since I am hearing a hum when it is engaged would it be reasonable to think something is shorting to ground?


Think, was the Electrolytic Capacitor the only thing you desoldered & turned around 2 times?
I ask this because if you removed a component that was awkward to remove, you may have damaged a trace!
The + & - Power pads on the PCB look really close to touching, Confirm you don't have Continuity there!!!!!!!! 
An audio probe is your only option if you are convinced your components & solder are Good!


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## megatrav

music6000 said:


> Think, was the Electrolytic Capacitor the only thing you desoldered & turned around 2 times?
> I ask this because if you removed a component that was awkward to remove, you may have damaged a trace!
> The + & - Power pads on the PCB look really close to touching, Confirm you don't have Continuity there!!!!!!!!
> An audio probe is your only option if you are convinced your components & solder are Good!


I have some solder wick and smaller solder coming in. 
I am going to try to redo some of my joints just to be sure. 

I only removed the capacitor once. It was the only component I removed, but I will check everything close by to make sure it's good. 

I will also check continuity at the +/- pads. 

Thanks again for all of the tips. I will report back after


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## megatrav

Checked and no continuity with the +/- pads. i assume that is a good thing.
I do have continuity between most of the grounds ( I didn't test them all)
I touched up a few pads but didn't have time to test. If it still isn't working, I may try swapping the SMD J201s for some through hole JFETs that I got from Mouser.
I am waiting for some parts to come in for the audio probe.


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## temol

If you have a guitar cable and a capacitor then you have an audio probe. Any capacitor... 47n...to 1u. Do not waste your time guessing the problem.


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## Harry Klippton

Audio probe saved my ass this week. Here's a good option if you feel a little intimidated by trying to figure it out on your own:



			https://diy.thcustom.com/shop/signal-tracer-injector-pen-v6-2/
		


DIYGP did a video on assembling and using it to test a circuit too. Very comprehensive


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## megatrav

temol said:


> If you have a guitar cable and a capacitor then you have an audio probe. Any capacitor... 47n...to 1u. Do not waste your time guessing the problem.


okay cool. I thought I needed to attach gator clips and all that. Any helpful diagram for how it should be connected? It would have to be something easily reversed


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## temol

Quick and dirty audio probe.

White wire - connect to GND (solder to PCB GND for example). 
Yellow wire - signal. Poke different areas of the pcb.. follow the audio path from input jack towards output jack. 

If you do not have a jack socket you can open jack plug and temporarily solder cap and GND wire inside jack. 
Connect the opposite end of the guitar cable to amp/headphone amp.. set vol almost to zero.


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## zgrav

you can make the yellow wire longer if you want to have a bit more flexibility while leaving the guitar cable on the table beside your PCB.


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## temol

Also you can put the cap at either end of the yellow wire. Get fancy...


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## temol

Follow the red line


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## megatrav

Question about the audio probe.. what should I be hearing?


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## temol

I assumed it's obvious that you have to inject a signal into the input.. anything.. mp3 player, phone, 1kHz sinewave (signal generator, audacity). Guitar is not the best choice because you probably need two hands to comfortably operate the audio probe.


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## megatrav

temol said:


> I assumed it's obvious that you have to inject a signal into the input.. anything.. mp3 player, phone, 1kHz sinewave (signal generator, audacity). Guitar is not the best choice because you probably need two hands to comfortably operate the audio probe.


Okay. So, let's say I use my phone and plug it into the input. Where does the output go? I am asking since I am using the input of my amp with a guitar cable. That cable has a Jack connected like the picture above. Ground connected to the ground of the Jack on the pedal (soldered on) and a 68n cap connected to the tip with a cable for probing. 

Would the probe allow me to hear the audio if I find the correct "bridge"? 

I'm just having a little trouble understanding how it works


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## megatrav

Am I silly and need to connect the cap and wire to the Jack on the pedal and not a separate one?


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## Mcknib

Separate

Like this quick one, as stated you don't need the clip on the ground side it's just easier to clip it to a ground point





Stick one end of your out cable in the probe jack the other to your amp as normal, ground it and probe the circuit with the probe end

Connect whatever you're using as audio into the in jack I use a looper pedal but you can use anything that plays audio


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## megatrav

I've been working on this build from guitar pcb mania. 
I have bypassed sound. No sound when engaged but I do have an LED. 
I took some shots of the board and I can't spot any bad connections so I think I might have the switch Ground and Control backwards. The PCB only says CNTRL.
I haven't tried swapping them yet but I wanted to post here to see if anyone might catch something else I may have done wrong. 









Thanks!


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## carlinb17

your input source ie. phone etc.. goes into the input jack of the pedal. The probe you made connects to the input of your amp or other speaker system, and then to ground on the pedal. When you make a connection on the solder joints indicated above (in red) you should hear your input sound. As you move down the line you will follow the sound and if it stops start there. Nothing goes into the output jack of your pedal, you complete the circuit by using the probe.


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## temol




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## megatrav

Makes perfect sense. Thank you!


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## megatrav

Okay so I know I am late to learning how the audio probe should be done. Thanks everyone who shared advice, pictures, and diagrams.

To test, I first touched the tip of the wire to the tip of the jack and I could hear the music coming through. I touched the In on the pcb as well as the spots on the footswitch and I could hear it as well.
Then, I went to C1 and I could not hear it when I touched the pads. I double checked and I don't see a bridge. The board does look a little brown from the iron, but I don't think anything is damaged?
Any thoughts?


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## zgrav

if you don't hear anythng at the capacitor it means the input is not reaching the capacitor.  bad connection.  you may have a damaged connection point between the input and the capacitor, or maybe just a bad solder connection.  touch up both of the capacitor leads on the PCB with your soldering iron and a bit of solder and see if you can get sound on either or both of the leads on the capacitor.


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## temol

You can reflow X-ed pad and make sure there's no solder bridge between those two pads and GND fill.


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## music6000

megatrav said:


> Okay so I know I am late to learning how the audio probe should be done. Thanks everyone who shared advice, pictures, and diagrams.
> 
> To test, I first touched the tip of the wire to the tip of the jack and I could hear the music coming through. I touched the In on the pcb as well as the spots on the footswitch and I could hear it as well.
> Then, I went to C1 and I could not hear it when I touched the pads. I double checked and I don't see a bridge. The board does look a little brown from the iron, but I don't think anything is damaged?
> Any thoughts?View attachment 16728





megatrav said:


> View attachment 16729


As t*emol* has pointed out:
1.Test for Continuity from Red Circle at C1 to Ground, Should not be!!!
2 Test for Continuity from Blue Circle ? at C1 to Ground, Should not be!!!
3. Test for Continuity between Red Circles.
4. Test for Continuity between Blue Circles
Has *C1* been removed or replaced prior to First Test of Build?


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## megatrav

music6000 said:


> As t*emol* has pointed out:
> 1.Test for Continuity from Red Circle at C1 to Ground, Should not be!!!
> 2 Test for Continuity from Blue Circle ? at C1 to Ground, Should not be!!!
> 3. Test for Continuity between Red Circles.
> 4. Test for Continuity between Blue Circles
> Has *C1* been removed or replaced prior to First Test of Build?
> 
> View attachment 16733


I will do that test today and no it has not been removed


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## music6000

megatrav said:


> I will do that test today and no it has not been removed


If all 4 Tests are Good, then you have a dud Capacitor which is rare!


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## megatrav

music6000 said:


> If all 4 Tests are Good, then you have a dud Capacitor which is rare!


Just did the test and it appears that I am getting continuity between C1 and ground (the 2 red circles in the below image) but not the black circle of c1 to ground.
I am also getting continuity in the places I am suppose to. So, I assume I need to clean off that ground pad and flow again?


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## temol

megatrav said:


> Just did the test and it appears that I am getting continuity between C1 and ground (the 2 red circles in the below image) but not the black circle of c1 to ground.
> I am also getting continuity in the places I am suppose to. So, I assume I need to clean off that ground pad and flow again?





If there's continuity between 0 and 2 there's also between 0 and 1. That's bad... cut the solder bridge between 2 and 0 (GND FILL) .. I assume 2 because it's a suspect (judging from the picture). Make sure there's no beep between 3 and 0, but should beep between 3 and 4.
And of course 1 to 2 should beep.
If you have a solder sucker then use it on 2.


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## music6000

megatrav said:


> Just did the test and it appears that I am getting continuity between C1 and ground (the 2 red circles in the below image) but not the black circle of c1 to ground.
> I am also getting continuity in the places I am suppose to. So, I assume I need to clean off that ground pad and flow again? View attachment 16738


Remove all Solder from Red Circle whish is going to Ground Plane ! :


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## megatrav

Okay so I cleaned off the joints and actually replaced the wires from the switch. With no wires connected there isn't continuity between the ground lug and c1 (red circle) but as soon as I put a wire in there is. Would this mean the switch is wired wrong/ has some sort of bridge or am I just wrong about that?


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## temol

Can you eliminate 3pdt from the equation? Just wire input jack directly to the pcb input. Same with the output jack.


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## megatrav

temol said:


> Can you eliminate 3pdt from the equation? Just wire input jack directly to the pcb input. Same with the output jack.


yes, I will do that in a bit. 
Should I remove all of the wires from the pads? 
If I do not have continuity would that mean it is the switch? 
I assume if there is continuity, then it would be a bridge somewhere?


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## temol

We'll find out. 
You can start with desoldering yellow wires where X-ed and conncting them to the input and output jack (tip). Make sure that you have GND connection between pcb and jacks.


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## temol

BTW.. make sure there's no solder bridge around IN solder pad from the components side.. I can see you have pretty big solder blobs there.


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## megatrav

Okay in and out pads wired to the jacks I have no continuity between c1 and the ground pad


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## temol

Good, but do you have any signal passing through? First, second, third transistor...? Forget about switch for a moment.


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## megatrav

temol said:


> Good, but do you have any signal passing through? First, second, third transistor...? Forget about switch for a moment.


Okay so aside from the in and out, the switch is still wired to the pedal. 
I have my audio probe set up and I did some testing.
Here is what I found-
If I connect the wire to the tip of the jack, I hear the audio. If the pedal is engaged (LED on) I get sound from the in pad on the pcb, but to c1. However, if the effect is bypassed (LED off) I do get audio at c1 and at the out pad


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## megatrav

I've been working on this build from guitar pcb mania. 
I have bypassed sound. No sound when engaged but I do have an LED. 
I took some shots of the board and I can't spot any bad connections so I think I might have the switch Ground and Control backwards. The PCB only says CNTRL.
I haven't tried swapping them yet but I wanted to post here to see if anyone might catch something else I may have done wrong. 









Thanks!


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## temol

no... you are bypasing the signal path through the switch. There's no engage or bypass for the audio now, it's on all the time. Switch only turns the led on.  At least in theory.... 
I'd desolder all the wires except in/out/supply to eliminate miswiring of the switch/led. Try not to lift the pads.


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## fig

Fantastic read and excellent troubleshooting folks. Hang in there @megatrav !


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## megatrav

music6000 said:


> In the Original wiring, was the Led OFF in Bypass & would Light up in the ON  position ?????


Yes the LED worked fine


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## music6000

megatrav said:


> Yes the LED worked fine


Remove the IN wire from the PCB & see if you have Continuity with *IN* pad & *Ground* pad on PCB!


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## megatrav

music6000 said:


> Remove the IN wire from the PCB & see if you have Continuity with *IN* pad & *Ground* pad on PCB!


I will definitely try this later


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## megatrav

I just want to say thanks @music6000 and @temol for chiming in and keeping at it with me. I'm learning so much


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## megatrav

Removing IN wire from PCB and IN and Ground do not have continuity @music6000


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## music6000

megatrav said:


> Removing IN wire from PCB and IN and Ground do not have continuity @music6000


Test* Ground* pad and Right side of *C1* pad pictured in Red Circle :


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## megatrav

music6000 said:


> Test* Ground* pad and Right side of *C1* pad pictured in Red Circle :
> 
> View attachment 16768


10-4. No continuity there either


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## music6000

megatrav said:


> 10-4. No continuity there either


Test Ground wire & IN wire on Footswitch for Continuity.
Should be in Bypass, Not in ON mode !!!
Test *Ground* Pad on PCB & Left* C1* Pad for Continuity.

UPDATE : I hope you don't have a Dud or Momentary Footswitch!!!!!


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## music6000

music6000 said:


> Test Ground wire & IN wire on Footswitch for Continuity.
> Should be in Bypass, Not in ON mode !!!
> Test *Ground* Pad on PCB & Left* C1* Pad for Continuity.
> 
> UPDATE : I hope you don't have a Dud or Momentary Footswitch!!!!!


I have to leave now for my 2nd Covid shot, No Retreat, No Surrender !!!


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## megatrav

Sorry, I was testing with the in and out jacks wired direct to the board. 
However, with it wired this way, using an audio probe, I get signal up until C4. No signal coming through there


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## megatrav

music6000 said:


> Test Ground wire & IN wire on Footswitch for Continuity.
> Should be in Bypass, Not in ON mode !!!
> Test *Ground* Pad on PCB & Left* C1* Pad for Continuity.
> 
> UPDATE : I hope you don't have a Dud or Momentary Footswitch!!!!!


I can't imagine I do have a momentary switch since the LED stays lit


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## megatrav

I should also mention that I am getting audio through the gate of Q1 but not the source or drain. Is that normal?


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## temol

megatrav said:


> I should also mention that I am getting audio through the gate of Q1 but not the source or drain. Is that normal?


No...
Yo have to inspect every solder joint on a pcb (both sides), make sure that transistors are seated firmly in the sockets. Also check the adapter boards for shorts.


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## megatrav

temol said:


> No...
> Yo have to inspect every solder joint on a pcb (both sides), make sure that transistors are seated firmly in the sockets. Also check the adapter boards for shorts.


I didn't take any pictures, but the solder joints look shiny to me. No bridges or anything either.  I also have continuity between the pads on the adapter board to the pads on the top and bottom of the main pcb


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## music6000

megatrav said:


> I didn't take any pictures, but the solder joints look shiny to me. No bridges or anything either.  I also have continuity between the pads on the adapter board to the pads on the top and bottom of the main pcb


Do you have the Adapter Boards in sockets or Soldered directly to main board?


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## megatrav

music6000 said:


> Do you have the Adapter Boards in sockets or Soldered directly to main board?


They are soldered direct to the board


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## megatrav

I would consider taking them out and putting in different ones but I don't think that is the issue. Maybe a trace is damaged somewhere?


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## temol

To verify this you can check continuity between transistor legs and components connected directly to transistor.
Connect one probe to transistor leg (adapter board seated in the socket), scond probe to the component leg connected to the transistor.  Continuity between legs of the components, not between solder pads.


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## megatrav

I've been working on this build from guitar pcb mania. 
I have bypassed sound. No sound when engaged but I do have an LED. 
I took some shots of the board and I can't spot any bad connections so I think I might have the switch Ground and Control backwards. The PCB only says CNTRL.
I haven't tried swapping them yet but I wanted to post here to see if anyone might catch something else I may have done wrong. 









Thanks!


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## music6000

megatrav said:


> I would consider taking them out and putting in different ones but I don't think that is the issue. Maybe a trace is damaged somewhere?


This is why I have asked if anything was removed from the Original Build up.
This is crucial as not knowing the quality of the board, any removal of any part in the original building of the Board could have damaged a trace.
This is why *temol* suggested the audio probe. this will tell you from the *In* to the *Out* highlighted in RED on the Schematic he supplied where the audio stops along the way is an Issue.
 You listed C4, Is that still an Issue?
*Q1 Drain *is ??????????????
 If so, Reflow it  & Test again!


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## megatrav

The only things I have removed


music6000 said:


> This is why I have asked if anything was removed from the Original Build up.
> This is crucial as not knowing the quality of the board, any removal of any part in the original building of the Board could have damaged a trace.
> This is why *temol* suggested the audio probe. this will tell you from the *In* to the *Out* highlighted in RED on the Schematic he supplied where the audio stops along the way is an Issue.
> You listed C4, Is that still an Issue?
> *Q1 Drain *is ??????????????
> If so, Reflow it  & Test again!


Okay to clarify, the only component I have removed from the original build is c10.

I get continuity when testing from the leg of the component on the adapter board to the corresponding pads on the adapter board and the back side of the main PCB. There is no continuity between each leg of the transistor (Q1). When using an audio probe, I can hear the audio when I touch Gate of Q1 but not the Drain or Source. Also, when I touch c4 I do not hear audio.

I'm not sure what I need to test at this point, I am doing my best to keep up with both yours and temol's instructions.


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## music6000

megatrav said:


> The only things I have removed
> 
> Okay to clarify, the only component I have removed from the original build is c10.
> 
> I get continuity when testing from the leg of the component on the adapter board to the corresponding pads on the adapter board and the back side of the main PCB. There is no continuity between each leg of the transistor (Q1). When using an audio probe, I can hear the audio when I touch Gate of Q1 but not the Drain or Source. Also, when I touch c4 I do not hear audio.
> 
> I'm not sure what I need to test at this point, I am doing my best to keep up with both yours and temol's instructions.


As* temol* has stated, You need to Test if you have Continuity from Transistor Legs to the Legs going to the Main PCB
Start with Q1 as that seems to have an issue :


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## megatrav

music6000 said:


> As* temol* has stated, You need to Test if you have Continuity from Transistor Legs to the Legs going to the Main PCB
> Start with Q1 as that seems to have an issue :
> View attachment 16777


yes, I have tested that and I do have continuity from the legs on the transistor to the pads on the bottom of the main pcb


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## megatrav

WAIT!

I forgot that I originally had the trimpot for the Gain+ and the trimpot for Q1 mixed up and I did have to remove them/swap them.
So, it is possible that I messed something up when I did that swap. How can I test?


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## music6000

Please remember, When using the Audio Probe to each component pad that there is *NO *flux residue or it will give a negative reading also!!!


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## music6000

megatrav said:


> WAIT!
> 
> I forgot that I originally had the trimpot for the Gain+ and the trimpot for Q1 mixed up and I did have to remove them/swap them.
> So, it is possible that I messed something up when I did that swap. How can I test?


Highly possible!!!
You said that Q1 trimmer adjusts so you have 4.5v, Is this still true, TEST AGAIN!!!


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## thesmokingman

I don't care to read through 6 pages of troubleshooting at this point but I would like to point out that this circuit is poorly designed with regards to the placement of the tone stack, volume pot, and the output. I strongly suggest acquiring a small buffer for insertion between the output of the circuit board and the stomp switch and see if that improves the overall sound as I suspect you're going to run up against impedance issues with the way that is drawn up in the build documents


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## music6000

thesmokingman said:


> I don't care to read through 6 pages of troubleshooting at this point but I would like to point out that this circuit is poorly designed with regards to the placement of the tone stack, volume pot, and the output. I strongly suggest acquiring a small buffer for insertion between the output of the circuit board and the stomp switch and see if that improves the overall sound as I suspect you're going to run up against impedance issues with the way that is drawn up in the build documents


He can find that out for himself if it Fires up !!!


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## thesmokingman

true ... should he get there it will probably sound ok on its own ... chained up with the wrong amp or pedal and he'll wonder why it sounds like there's been a blanket thrown over the toanz


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## music6000

music6000 said:


> He can find that out for himself if it Fires up !!!


Gain + Continuity Test, Green Circle goes to GROUND :


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## temol

Troubleshootign is getting harder and harder with every step here. Too many variables. 
- you have a signal on  Gate of Q1 - where exactly? capacitor in front of the G? Solder pad of the socket? inside the socket? solder pad on a daughterboard? Transistor leg? Can you swap places q1 and q2?
- do you have 4.5V or 1/2 of the Vcc on a Drain?


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## megatrav

Okay I'm sorry this became a 6 page thread. 
My voltages are all over the place now. 
I swapped the trim pots because I couldn't get it low enough to 4.5v. Now, when I test Q1 the lowest I can set the voltage is 6.3. 

I think I am going to put this one on the shelf for at least a few days and move on. 

It was fun learning ways to trouble shoot issues but this has gotten to the point of frustrating. 

Maybe this one is just a terrible design or maybe I messed it up. Or maybe the jfets I have are bunk. I have no idea. 

Thanks for all of the replies. I will report back if I'm able to find anything else out


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## megatrav

music6000 said:


> Gain + Continuity Test, Green Circle goes to GROUND :
> View attachment 16780


yes, the red and blue have continuity


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## Feral Feline

megatrav said:


> Okay I'm sorry this became a 6 page thread.
> ...


No need to apologise.

Plenty of other troubleshooting threads have surpassed the six page mark, and besides... the purpose of the Troubleshooting Sub-forum is to to troubleshoot. 

While I wasn't able to be of much assistance, there's been plenty of good guidance from better minds/more experienced people; sharing the  experience potentially benefits others — so whether a 2-page thread or a 10-page thread, it has value.

I have a vested interest in your success, as I have the same PCB waiting to be built.

Putting this project down for a while might be just what is needed to be able to gain a fresh perspective and potentially bring the thread to positive fruition.


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## music6000

Feral Feline said:


> No need to apologise.
> 
> Plenty of other troubleshooting threads have surpassed the six page mark, and besides... the purpose of the Troubleshooting Sub-forum is to to troubleshoot.
> 
> While I wasn't able to be of much assistance, there's been plenty of good guidance from better minds/more experienced people; sharing the  experience potentially benefits others — so whether a 2-page thread or a 10-page thread, it has value.
> 
> I have a vested interest in your success, as I have the same PCB waiting to be built.
> 
> Putting this project down for a while might be just what is needed to be able to gain a fresh perspective and potentially bring the thread to positive fruition.


Good Luck trouble shooting this one, the GAIN Pot is on the Top Right outside of the Main Schematic!


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## Feral Feline

music6000 said:


> Good Luck trouble shooting this one, the GAIN Pot is on the Top Right outside of the Main Schematic!


I never said that the troubleshoot would not result in the finding of this circuit being inherently incorrect!

Such a conclusion would _still_ be a successful troubleshoot; success isn't measured by an operable circuit alone.


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## megatrav

Thanks everyone for the encouragement. I am at least taking the weekend off from building/working on anything. 
I was really hopeful that this would be my answer to not buying a Rockerverb but as many have stated, the circuit itself is flawed.

I think that maybe GuitarPCB Mania projects aren't as great overall. I am also building a "Sea Lion Compressor" from them and it has been a headache as well


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## megatrav

Just a little update.
I removed the boards with the jfets and installed some other ones direct on the pads. I am still not getting audio but I am getting the LED turning on and off with the switch.
I also have bypassed signal still. Just nothing when engaged.
I am going to do some testing with the audio probe tonight or tomorrow.

If it appears to still not work, I am going to cut my losses and probably just order a new board at some point.
Here is a pic of the transistors on the board.




Please excuse the marred capacitors. It was a tight spot


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## temol

Now it's reading the leaves... you should test the board with the audio probe before you make any further changes .. just leave the board as is.


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## megatrav

I've been working on this build from guitar pcb mania. 
I have bypassed sound. No sound when engaged but I do have an LED. 
I took some shots of the board and I can't spot any bad connections so I think I might have the switch Ground and Control backwards. The PCB only says CNTRL.
I haven't tried swapping them yet but I wanted to post here to see if anyone might catch something else I may have done wrong. 









Thanks!


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## megatrav

temol said:


> Now it's reading the leaves... you should test the board with the audio probe before you make any further changes .. just leave the board as is.


I finally had a chance to do some testing today.
Tracing the signal path, I get audio from In, C1 and R1.. here is where things get interesting. 
I get audio when I touch the prove to the Gate of the actual transistor but not the Source or Drain legs.
However, just out of curious I put the leg of the probe where the holes for the through hole transistors go and I get audio at the spot where the Source leg would go but not the other 2. 
Anyway, I am open to any suggestions


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## temol

Problem - signal does not pass through multiple points of connection.
Action - inspect connection points.

You have a:  pcb trace, solder joint, transistor legs, transistor itself. 
It's a fairly simple set. 

My first thought - connectivity issue. Damaged trace, damaged solder pad, bad solder joint, short. And then maybe I'd check transistor.. it's not easy to fry a transistor (in my opinion) but it's of course possible.


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## megatrav

temol said:


> Problem - signal does not pass through multiple points of connection.
> Action - inspect connection points.
> 
> You have a:  pcb trace, solder joint, transistor legs, transistor itself.
> It's a fairly simple set.
> 
> My first thought - connectivity issue. Damaged trace, damaged solder pad, bad solder joint, short. And then maybe I'd check transistor.. it's not easy to fry a transistor (in my opinion) but it's of course possible.


I think I can rule out the transistor since I am using a different one than I was using before but I will continue to investigate the issue. thank you for the responses


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## music6000

megatrav said:


> I finally had a chance to do some testing today.
> Tracing the signal path, I get audio from In, C1 and R1.. here is where things get interesting.
> I get audio when I touch the prove to the Gate of the actual transistor but not the Source or Drain legs.
> However, just out of curious I put the leg of the probe where the holes for the through hole transistors go and I get audio at the spot where the Source leg would go but not the other 2.
> Anyway, I am open to any suggestions


Which Transistor are you referring to, Q1????


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## megatrav

music6000 said:


> Which Transistor are you referring to, Q1????


Yes Q1. That is as far as I have tested. I assume that I should hear audio through all three parts of the transistor when using an audio probe?


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## music6000

megatrav said:


> Yes Q1. That is as far as I have tested. I assume that I should hear audio through all three parts of the transistor when using an audio probe?


You may need to do this if no audio on one or more of the 3 larger Pads! 
Jumper and Solder to each one :


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## megatrav

music6000 said:


> You may need to do this if no audio on one or more of the 3 larger Pads!
> Jumper and Solder to each one :
> 
> View attachment 17452


I will give that a shot. Thank you!


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## temol

If I may suggest - try to minimize soldering at this point. Now,  with every soldering action you risk damage to the board. Take some isopropyl alcohol and clean flux residue. There's some burnt gunk around the pads and this does not help you and us to spot potential issues.


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## megatrav

temol said:


> If I may suggest - try to minimize soldering at this point. Now,  with every soldering action you risk damage to the board. Take some isopropyl alcohol and clean flux residue. There's some burnt gunk around the pads and this does not help you and us to spot potential issues.


that is solid advice as well. I have been cleaning with alcohol after each time I do solder. 
I am not very hopeful about this project working out, so I am going to see what I am able to do to get it working.


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## megatrav

Just wanted to do a quick update. I reached out to GuitarPCBMania via Facebook. 
After a few questions, he recommended to try connecting a 1 Meg resistor from the transistor to ground like this:






So I am going to give that a shot and see if there is any difference


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## megatrav

I installed the 1meg resistor per his instructions and sadly it made no difference.
Using an audio probe I get signal from the in>C1>R1>Q1 gate. I do not get audio from the Source or Drain from Q1.
The signal does go beyond that to C4. However, the quality begins to sound choppy, distorted, and degraded. Not clear at all. 
I am able to keep getting signal until I get to Q2, including the preamp pot, however the audio is still degraded. 
It stops once I get to Q2.
So, either the issue starts at C4 or Q2?


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## temol

Lets forget about Q1 for a while. Inject signal to Q2 instead. I think that easiest way would be to connect alligator clip or solder a wire to leg 2 of the Preamp potentiometer. Or leg 3.


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## megatrav

temol said:


> Lets forget about Q1 for a while. Inject signal to Q2 instead. I think that easiest way would be to connect alligator clip or solder a wire to leg 2 of the Preamp potentiometer. Or leg 3.


Okay I will try that next!


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## megatrav

@temol I did as you instructed and I do not get signal at any points of Q2 with the ground attached to leg 2 or 3 of the preamp pot


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## temol

No,  not the GND. You have to connect your test signal there. Guitar, mp3 player, finger...  Leave GND as is.


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## megatrav

temol said:


> No,  not the GND. You have to connect your test signal there. Guitar, mp3 player, finger...  Leave GND as is.
> 
> 
> View attachment 18196


gotcha. I did that previous and when I touch and of those points where the arrows are, I get very distorted and almost static like audio with the song that I'm playing through my phone. 
It starts to become distorted/static after Q1


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## megatrav

I will do some more testing tonight. I wish there was an easy way to record what I am heading, but I am doing testing through headphones since that is what I have to work with


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