SOLVED LED Dimly Lit In Bypass

[Ginsly]

Are there any “most likely” reasons for this? I just put together a PPCB-style fuzz board (Fig Buster - thx @KR Sound!) and I’m having this problem. I did add a battery snap, and that’s how it’s powered. I also used a PPCB footswitch pcb.

Pedal seems to work normally other than the LED staying VERY dimly lit when in bypass. I repurposed an old enclosure and used off-board pots because of that. Also added some screw terminals, which I think over complicates things . No solder bridges that I can see…

I’m away but will add pics later- apologies. Just wanted to see if there were certain things to look at when this happens. Much appreciated!

 

[jimilee]

Are you talking about the clipping diodes?

 

[Ginsly]

Are you talking about the clipping diodes?

Nope, I changed out the main power LED that’s exhibiting the problem. I figured the clipping LEDs wouldn’t have anything to do with it so I left em.

 

[jimilee]

Nope, I changed out the main power LED that’s exhibiting the problem. I figured the clipping LEDs wouldn’t have anything to do with it so I left em.

I was just making sure we weee talking about the same ones. Did they come from Tayda?

 

[VanWhy]

That is odd. I doubt it's two bad footswitches. . I thought for sure swapping the switch would have done it. Hopefully someone else has a suggestion.

 

[Ginsly]

I was just making sure we weee talking about the same ones. Did they come from Tayda?

Gotcha. Nope I've had these leds for a while, came in some sort of kit a while back. Work well in everything else. Why, is Tayda bad for LEDs?

That is odd. I doubt it's two bad footswitches. . I thought for sure swapping the switch would have done it. Hopefully someone else has a suggestion.

No big thing, thanks man! I just went back to my janky stripboard Fig Buster and cleaned it up a bit. I depopulated the PCB in case I want to start from scratch. We'll see!

 

[jwin615]

Are you using a ppcb 3pdt board or the other?
If the other, I don't think you need the led pad connected at all.
The entire led circuitry is onboard. DC in, switch, ground and led are all there.
If you are using the other 3pdt board, can you post pics of how it's connected?

 

[Ginsly]

@jwin615 Nope I used a normal 6-pad PPCB board. Tried another PPCB board with a new switch and same thing happened. Very weird!

Although this one may remain unsolved, I'm VERY much in need of some detailed guidance if I DID use a board like this (below) for my CLR, LED, all Jack connections, and DC wires when using a PedalPCB board:

Sounds like I have to jumper the CLR and LED pads on the main PCB, but other than than I'm not sure what I'd need to do. I add battery snaps and use side jacks, so having most of the wiring go through the 3PDT PCB would be great. I use these when I build on stripboard and love em!

 

[jimilee]

Gotcha. Nope I've had these leds for a while, came in some sort of kit a while back. Work well in everything else. Why, is Tayda bad for LEDs?

Tayda is where we for the bad blue LEDs.

 

[KR Sound]

I'm the culprit. He's doing everything correct.

When I made the pcb, I swapped the SW and GR in the version I sent him.

So, just swap the G and SW wires, and you'll be all set.


I deserve to use white washers for the rest of my life.


Here's what he has and what I had produced:





And here's when I fixed it and didn't get any more made:




Sorry! I messaged you @Ginsly

 

[jwin615]

@jwin615 Nope I used a normal 6-pad PPCB board. Tried another PPCB board with a new switch and same thing happened. Very weird!

Although this one may remain unsolved, I'm VERY much in need of some detailed guidance if I DID use a board like this (below) for my CLR, LED, all Jack connections, and DC wires when using a PedalPCB board:
View attachment 68719
Sounds like I have to jumper the CLR and LED pads on the main PCB, but other than than I'm not sure what I'd need to do. I add battery snaps and use side jacks, so having most of the wiring go through the 3PDT PCB would be great. I use these when I build on stripboard and love em!

Yes, just jumper CLR and led. Can use an extra component lead or buy some 0 ohm resistors if you want to be fancy.
At that point, SW is 9v.
Hook your battery snaps at the north side of the board, red to positive, black to the switch on the DC jack or negative if not using the DC jack

 

[jwin615]

I'm the culprit. He's doing everything correct.

When I made the pcb, I swapped the SW and GR in the version I sent him.

So, just swap the G and SW wires, and you'll be all set.


I deserve to use white washers for the rest of my life.


Here's what he has and what I had produced:

View attachment 68729

View attachment 68730

And here's when I fixed it and didn't get any more made:

View attachment 68725


Sorry! I messaged you @Ginsly

Womp womp

 

[KR Sound]

Womp womp

I’m ashamed and feel like poop for causing multiple days of headaches and frustration. I should’ve realized it when I saw the board.

 

[Guilherme Collateral]

This! Happened exactly the same with me, after countless hours of tests and swearing, I replaced the LED and the problem was gone

I had this exact same problem last year. After eliminating all possible problems with power, ground, switches, etc. it turned out that particular batch of blue LEDs I bought were the issue (I was able to reproduce the problem another way).

IIRC, jimilee had the same issue with a different set of blue ones. Maybe we bought them from the same source.

 

[Giorfida]

Tayda is where we for the bad blue LEDs.

I know the Tayda 3mm red LEDs clip differently than the scAmazon special 5mm red LEDs I have. Built a GuvNor with the 5mm, and the Appetizer with the 3mm, and the GuvNor (same circuit up to the clipping, except using a tl072 instead of 4558), and it has significantly more dirt on tap, so unless a TL072 is hotter (shouldn’t be), tells me the 5mm diodes have a lower threshold

 

[eh là bas ma]

I deserve to use white washers for the rest of my life.

I am not sure that i fully understand this sentence.

Do you mean that you deserve to be deprived of plastic washers for ever ? But why would you punish these poor and lonely 3PDT, and ruin your enclosures's good looks for something they didn't do ?

I think a no-plastic-washer life sentence would be unfair and cruel. I am sure @Ginsly would agree.

May i suggest a few other interesting punishments ?

No more led metal bezels, and only use the weirdest knobs for 10 years, that would surely be more effective as a punishment, and much more interesting for your enclosures's good looks.

Or being forced to install either your DC power jacks or your output jacks on the bottom side of every enclosures (yes, under the stompbox), for all your future builds, for ever.

Or the penalty to use only super bright white status led with 1k led resistor, and the obligation to do the necessary modifications on all your previous builds. Sunglasses are not allowed.

 

[Ginsly]

Haha... All good, everybody! I'm honestly just happy I did everything right! I guess this mystery is solved, and I really appreciate all of the troubleshooting tips. I'm sure I'll need more in the future, and it likely WILL be my fault! Ha...

Yes, just jumper CLR and led. Can use an extra component lead or buy some 0 ohm resistors if you want to be fancy.
At that point, SW is 9v.
Hook your battery snaps at the north side of the board, red to positive, black to the switch on the DC jack or negative if not using the DC jack

@jwin615 thanks for your help clearing this up! I might be misinterpreting what you're saying, but is the below diagram right? I use stereo jacks, and usually connect red (+) battery snap lead to middle DC Jack lug, and black (-) battery snap lead to the Ring of the Input jack. In that case I wouldn't connect anything at all to the +,-, and two ground pads at the top of the main pcb? I'm also not sure if you were saying to connect SW on the main board to "9V" on the footswitch board like this:

 

[jwin615]

I was suggesting connecting your DC at the top of the board like usual then pulling 9v/SW to the 9v spot on your daughter board just to power the LED.
The way you have drawn it *should* work on this pedal but I wouldn't bet it to work on every circuit. If the onboard led power ever branches after the input protection and filtering cap, wiring it this way would bypass all of that, for instance.
I would send power through the top of the pcb to avoid *potential* issues. Anything with a charge pump could spell problems as well.

 

[Robert]

I'm confused.

I thought the original complaint was that the LED was dimly lit in bypass?

An LED can't light, bright or dim, defect or not, if there is no ground path.... which there should not be when the pedal is bypassed if it is wired up properly.


Does the LED light normally when the pedal is active?


Nevermind, I'm caught up now.

 

[Ginsly]

I was suggesting connecting your DC at the top of the board like usual then pulling 9v/SW to the 9v spot on your daughter board just to power the LED.
The way you have drawn it *should* work on this pedal but I wouldn't bet it to work on every circuit. If the onboard led power ever branches after the input protection and filtering cap, wiring it this way would bypass all of that, for instance.
I would send power through the top of the pcb to avoid *potential* issues. Anything with a charge pump could spell problems as well.

Gotcha. So I could link the DC jack to the top + and - on the main pcb like you mentioned, and then hook my battery snaps up like in my diagram? Then I would connect In to In, Out to Out, Ground to Ground, and SW to 9V at the bottom?

I thought the original complaint was that the LED was dimly lit in bypass?

Apologies for any confusion, I'm clearing up another question about using a different style 3PDT pcb with a PPCB board, which was something I was going to try if I had to continue troubleshooting. It's something I've been wondering about anyways.

The original problem was indeed that the LED was dimly lit in bypass, and that's evidently because KR had swapped the G and SW pads on the main PCB. I'm as shocked as anyone that it wasn't my fault! Ha...

 

[Robert]

The original problem was indeed that the LED was dimly lit in bypass, and that's evidently because KR had swapped the G and SW pads on the main PCB. I'm as shocked as anyone that it wasn't my fault! Ha...

Haha yep, I see now.

This is similar to what I was suspecting, except your LED was "grounding" to the INPUT rather than the OUTPUT. (In the latter case the volume control would control the LED brightness)