Delegate Boneyard has LED turning OFF

[Dali]

I just finish a Delegate Boneyard Edition.

When I turn on 9v, the 5mm Transparent LED goes on for 2 seconds then fade out. Same thing for the sound.

If I play during those 2 seconds with the pedal engage, I got sound for those 2 seconds then it vanish.

If 3PDT is OFF the pedal being bypassed, the sound reach the amp but obviously, no effect.

I triple check soldering, LED +/-, orientation of diodes and electrolytics.

What on Earth would make a LED turn off?

 

[Dali]

And the pictures...

 

[fig]

You'll probably need to conceal the LDR, since you have other LEDs installed on the side of the pcb.

 

[Barry]

My guess would be a faulty capacitor

 

[Dali]

You'll probably need to conceal the LDR, since you have other LEDs installed on the side of the pcb.

Understood but this has no direct effect on the fact that the White LED get on then off, correct?

 

[fig]

Barry's response is likely closer to the issue. The fact that it is on and fades sounds like a cap discharging?

Still, I recall the LED fading on my build with the back off...

 

[fig]

By the way, that's a very clean board! Nice work!

 

[fig]

Okay, easy enough to check...4 screws....it does fade after power up with the lid off.

 

[caiofilipini]

By the way, that's a very clean board! Nice work!

I was actually going to ask how he cleaned it. I've been using the IPA+toothbrush trick and I can get the solder side pretty clean, but some flux residue ends up on the component side after that and it's really tough to get it out. Tips?

 

[Feral Feline]

Yes, Q-TIPs

 

[Dali]

I was actually going to ask how he cleaned it. I've been using the IPA+toothbrush trick and I can get the solder side pretty clean, but some flux residue ends up on the component side after that and it's really tough to get it out. Tips?

Got a bad news for you.

I didn't cleaned it. Nothing. Zero. Nada. Rien.

I will change and test capacitors, one at a time.

 

[Barry]

Got a bad news for you.

I didn't cleaned it. Nothing. Zero. Nada. Rien.

I will change and test capacitors, one at a time.

I'd start checking the electrolytics first

 

[music6000]

Got a bad news for you.

I didn't cleaned it. Nothing. Zero. Nada. Rien.

I will change and test capacitors, one at a time.

Can you make sure your Transistors are making good contact first, especially MPSA18, I dont trust those sockets at all on any build!
Did you run some Solder on the legs so they fit tighter. If not, do it!!!

 

[fig]

@Dali

I thought you trying to use the pedal with the cover removed. My apologies.

 

[EGRENIER]

If I understand how this circuit work, and I may not, the compression comes from the LDR when the LED goes on and off...

When I tested mine, I tested it in complete darkness... one to allow the LDR to read the LED light and not the ambient light and two to see if the clear LED was going on and off when strumming.

If I remember well, the LED should go on when signal is coming through and off when no sound....

Did you try testing it in the dark ?

 

[Dali]

Can you make sure your Transistors are making good contact first, especially MPSA18, I dont trust those sockets at all on any build!
Did you run some Solder on the legs so they fit tighter. If not, do it!!!

Will do for sure.

So far I used them on about 10 pedals without worries but in this case you may be right!

 

[Dali]

Did you try testing it in the dark ?

Yes, I think the led lighting on "startup" is not a problem after all.

It really looks like a bad contact along the line. I will work on it tomorrow.

 

[Chuck D. Bones]

The LED flashing during startup is normal.

I don't recommend pulling parts off to test them because you will wear out the board pretty quickly doing that.

We can measure some DC voltages with the power on and get a pretty good idea what is good and what is not.

It is not necessary to shield the LDR from the internal red LEDs because they only come on very briefly, if at all, and if they do come on, it's happening at the same time that the white LED is starting to turn on.