LED not working - please help!

[pereubu]

Hi all. need some help again. I have built a Fuzz pedal (http://www.parasitstudio.se/uploads/2/4/4/9/2449159/eagle_claw_doc.pdf)
It all works when tested, then I do all the offboard wiring (with a daughter board), and even though it still works the LED doesnt.
I changed the connecting wires but that didnt work, and then tested the LED itself, and it is fine. I also changed the CL Resistor which is a 2K2 (could that be the issue??)..
still nothing. Am I missing something else or do I need to just redo all the above?
Thank you all.

[mcknib]

Hi Pereubu,

Is your LED on the daughterboard? sounds like it may just be either the wrong way round i.e ground going to anode + and power going to cathode - obviously not if you mean you changed the connecting wires to the LED , it's not grounded or powered or both or the legs are shorting on something. Do you have it going up into a metal bezel? if so perhaps the legs are touching it when you push it up into it.

[pereubu]

Thanks, dont think the legs are shorting as I checked it with a multimeter with it still installed in the holder/bezel thing.
Have checked the leads, square hole on dboard goes to + (long leg) on LED, round hole to neg (short leg). Confused! Do you know if the 2k2 is the correct resistor to have on this?

[mcknib]

The CLR value in this case wouldn't matter as long as it's not open /short circuit and falls within the normal range 1K to 4K7 is what I use depending how bright I want it.

Make sure it's a 2k2 it'd need to be pretty big to stop it getting the required voltage 2m2?

Have you checked your getting voltage on the LED anode leg

Is it a metal bezel?

Do a continuity check on the wires, resistor, LED part of the circuit to check it's got good connection and you don't have a dry solder joint somewhere. You could also continuity check the LED legs when it's in the bezel see if one or both beep against the bezel if it's metal, if you continuity check the LED legs when up in the bezel and it lights then they're not shorting obviously if it beeps they are so just use some stripped off wire insulation to insulate them

[pereubu]

Ok so. New wires, new resistor. All hooked up. Tested continuity, each item is working fine, led lights up with the multimeter, resistor shows 2.2, even tested where the leads enter the pcb and he led lights up so everything is connected and working. There must be an issue with getting power to the led when its switched on??! Or the resistor isnt correct?? Could it be the pcb? Rest of the unit works fine though.

[pereubu]

Also, I just changed Resistor to a 4.7. No help. Switched wires around from led to pcb daughterboard just in case. No help. I have no idea what to try next. Is part of the daughterboard damaged? So that the switch isnt getting current to the LED? Pedal works as it should in every other respect! Whoever can figure this one out is a genius, I'm stumped.

[mcknib]

Did you take voltages on the LED legs in both on and off modes

Is your 3pdt also soldered to the daughterboard

If you can post an image of it and your wiring to the daughterboard

[pereubu]

I installed battery, and when switched off I used continuity/buzzer setting on multimetre, reading is 1 and LED light up,
when switched is on howeverit buzzes and the reading is -863.

[pereubu]

Ok, I check voltages of battery input, then led, then ground on battery input to + on led etc.
Some readings were 7.7, and then at the led they were -7.7.
Figured leads get switched. Changed and they are all working now, LED lights up! Thanks so much for your patience!
I am sure I changed the leads a few times already,but maybe also there were other issues like lead strands touching/short circuit.
Anyway, Im really happy, and I learned more along the way. Its a long journey! Now. need to tidy up my wiring cos its a mess!
Thank you again for you help.

[mcknib]

Great glad its working sometimes you just hit a blank debugging I know I do now and then but as you say it's a good learning process you learn to take a break from it before you toss it out of the window haha