# Dying LED no sound



## Dali (Jan 1, 2020)

I'm confused.

I just built my first pedal of the year, a Kaleidoscope and it worked perfectly unboxed for the 5 minutes I tried it. I boxed it after diner and saw that my blue 3mm LED was a bit pale. I set the pedal to OFF and plug the guitar. Bypassed I hear the guitar but when engaged/ON, there's no sound at all and the LED doesn't lit anymore at all.

What could be wrong?


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## Robert (Jan 1, 2020)

Something made contact somewhere it shouldn't.

Got a DMM?  

Measure the DC voltage across the two lugs of the DC jack, then check the voltage on Pin 8 (to ground) of either of the TL072's.


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## Dali (Jan 1, 2020)

I have a multimeter but I still don't know how to use it.

I unboxed it and works again.

I think I found the culprit, it's a B10K that has no plastic cover like most Tayda ones. It probably was touching the board where the arrow is pointing:


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## Robert (Jan 1, 2020)

That'll do it.   Outside of the box the metal case of the pot is floating so it doesn't cause a problem... Once you install it in the enclosure it's a dead short to ground.

Take one off one of the other pots, they're removable.


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## Chuck D. Bones (Jan 4, 2020)

Jovi recommends spacing the pots up off the board, see the Basic Workflow Tips.  Make sure the leads are trimmed short on the solder side.  You didn't actually use a dual pot like the picture shows, right?


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## Dali (Jan 4, 2020)

Chuck D. Bones said:


> You didn't actually use a dual pot like the picture shows, right?



I did but cut the "closer to the pot" pins first.

I bought 5 of them by accident on my last Tayda order. Yeah, I suck.


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## Robert (Jan 4, 2020)

Ahh yeah, I remember you mentioning the dual pot mishap now....

Dust caps won't fit on those, when I use them I stick an adhesive rubber pad on the back to keep the PCB spaced far enough.









						Self Adhesive Rubber Feet - PedalPCB.com
					

Self Adhesive Rubber Feet




					www.pedalpcb.com


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## phi1 (Jan 4, 2020)

I use this _*double sided foam tape*_ for many situations like this.


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## Dali (Jan 4, 2020)

phi1 said:


> I use this _*double sided foam tape*_ for many situations like this.


What? It happens often? 

Thanks for the tip. I feel less alone now.


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## phi1 (Jan 4, 2020)

Haven’t had this situation exactly, but I use this tape often when I’m trying to fit mods in like _*this*_.


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## Chuck D. Bones (Jan 4, 2020)

Dali said:


> I did but cut the "closer to the pot" pins first.
> 
> I bought 5 of them by accident on my last Tayda order. Yeah, I suck.



I've put dust caps on dual pots.  Takes a little trimming of the cap to fit around the leads, but it works.


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## Mourguitars (Jan 4, 2020)

Dust Cover For 16mm Alpha Pots
					

Small Bear Electronics DIY Parts




					smallbear-electronics.mybigcommerce.com
				




I bought 30 of these because Mouser and BLMS  pots dont ship with dust covers...with my very first build i had a A5 that wasn't PCB mount that was shorting out the board was free floating banging and rattling around...duh !

They will fit just a little Trim for those duel leg pots, just like Chuck said

Mike



https://imgur.com/uyzlPZI


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