Lemon Rockerverb- no sound when engaged

megatrav

Active member
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.
D8E1A375-3995-4E14-B3DE-0B7D22196D96.jpeg 1356B69E-4BEF-4727-9D34-25382E24CF51.jpeg CF32E9F3-AD5D-4D76-9638-E0652C9C6873.jpeg 7C420E8D-B9B7-4F23-987C-2DAC7BFF7725.jpeg
Thanks!
 

carlinb17

Well-known member
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.
 

megatrav

Active member
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? 220E88F6-2F1D-456F-87EC-A9B51CB9373C.jpeg 4E57B97C-5E22-40FA-8A60-00356E4D6397.jpeg
 

zgrav

Well-known member
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.
 

music6000

Well-known member
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

As temol 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?

Lemon Rock Continuity Test.jpg
 

megatrav

Active member
As temol 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
 

megatrav

Active member
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? Lemon Rock Continuity Test 2.png
 

temol

Well-known member
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?
1633534672525.png
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.
 

megatrav

Active member
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?
 

megatrav

Active member
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?
 

temol

Well-known member
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.

1633540827071.png
 

megatrav

Active member
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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