LED always on in Trembling Loon

[rozencratz]

Hi All,
I've read all the forum answers on this and have still hit a roadblock. LED 1 and LED 2 stay on regardless if the effects are on and I can't figure out why. I have confirmed that the switch is not the issue. The switch LED comes on and off as appropriate, the effect turns on and off as expected too. I tested continuity on the switch and confirm the circuit is open at the center middle and center top lugs when the switch is on bypass and closed when engaged. The LEDs are otherwise functioning as expected with all potentiometer adjustments and I can use the pedal. But those LEDs are just permanently on.
I've checked and cleaned every solder joint and nothing changes.
I tried looking at the schematic to figure out where a potential accidental ground could be for both LED 1 and 2 and still can't find anything.
You'll see I haven't even soldered in LED 1 yet so I really don't get how that can also have a bad ground somewhere
Would appreciate any insight.

 

[gtfields13]

Maybe an obvious question, but shouldn't these be on when there is power to the pedal?
Just looking at the circuit, there is nothing that switches the LEDs off. Are they visibly oscillating in intensity? Are you not getting the tremolo you expect?

 

[PJS]

Yes, it looks like normal operation for them to be working whenever the power is applied. Obviously the the one inside the case doesn't matter too much. The one outside the case will give you a visual idea of the rate it is set to before you engage it - just to make sure it seems right and the knobs haven't been changed. If you want to change that behaviour you could lift the end of the attached resistor that goes to ground and attach it to the SW pad instead. Then it will only work when the pedal is engaged

 

[rozencratz]

So I guess I made an assumption that one of the LEDs was for external so I could see the oscilations. However, is that not the case and perhaps both LEDs should be pointing at the LDR?
The issue is the one I assumed that was for external use would be always on and always oscillating, even when the pedal is off. And that’s just annoying to have on my board.

 

[rozencratz]

Yes, it looks like normal operation for them to be working whenever the power is applied. Obviously the the one inside the case doesn't matter too much. The one outside the case will give you a visual idea of the rate it is set to before you engage it - just to make sure it seems right and the knobs haven't been changed. If you want to change that behaviour you could lift the end of the attached resistor that goes to ground and attach it to the SW pad instead. Then it will only work when the pedal is engaged

Yeah sounds like I did it right but just misunderstood how the external LED was meant to function.

 

[BrainDrain]

Yeah sounds like I did it right but just misunderstood how the external LED was meant to function.

It can be nice to have in some pedals to give you a visual cue of the effect rate on a dark stage before you switch the effect on.

 

[gtfields13]

It can be nice to have in some pedals to give you a visual cue of the effect rate on a dark stage before you switch the effect on.

I think this is the reason - you could also add a resistor or use a lower output LED to adjust the external LED's brightness.