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Projects => Tech Help - Projects Page => Topic started by: decsnspace on August 01, 2013, 08:58:33 PM

Title: Mudbunny (green russian 1st build) - Pedal works but LED doesn't light
Post by: decsnspace on August 01, 2013, 08:58:33 PM
I've just finished building a green russian mudbunny.
The pedal works great and sounds really good, but the LED doesn't come on when the pedal is on.

The mudbunny build pdf doesn't show the chasis wiring, so I just followed the standard madbean pedal wiring on the project home page: http://www.madbeanpedals.com/tutorials/downloads/StandardWiring_MBP.pdf (http://www.madbeanpedals.com/tutorials/downloads/StandardWiring_MBP.pdf)

I've wired the pedal using the 4.7k resistor shown and I am also using a 3mm Green LED.

Based on the wiring diagram I used any ideas of what I may need to do to get the LED to turn on?
Title: Re: Mudbunny (green russian 1st build) - Pedal works but LED doesn't light
Post by: jkokura on August 01, 2013, 09:10:16 PM
Usually, a non-lighting LED means one of two things - it isn't wired right, or the LED is burnt out. It tends to be the not wired correctly meaning, but occaisionally the other.

You'll need to either take good pictures of your wiring, or perhaps triple check them for yourself. If you're confident you've done it right, start with the assumption that you're wrong, and then prove yourself correct (meaning, don't assume it's right). After that, come let us know what's up.

Jacob
Title: Re: Mudbunny (green russian 1st build) - Pedal works but LED doesn't light
Post by: jimilee on August 01, 2013, 09:13:16 PM
Ive built just a real whole bunch of pedals and I bet half of them I either A) wired the LED backwards or B) Forgot the resistor and burned it right out. Now let me say that I have the wiring diagram right in front of me every single time I do this. Happens to every one of us more than once.
Title: Re: Mudbunny (green russian 1st build) - Pedal works but LED doesn't light
Post by: wstimson on August 01, 2013, 09:59:59 PM
If you are sure you have it wired correctly, then it is either backwards or a bad LED, most likely.
Also, make sure you don't have it wired to the other power lug (the one for the battery).  I've seen that done once or twice. 
Title: Re: Mudbunny (green russian 1st build) - Pedal works but LED doesn't light
Post by: decsnspace on August 01, 2013, 11:29:44 PM
Thanks for the replies. I was just testing it out again with the back open and LED lit up on a few occasions when I pressed the switch and then sometimes would either flicker or not light up at all. I'm guessing there must be a short somewhere or a cold solder joint. Looks like I'll need to do some more investigating and maybe re-flow some of the solder joints that connect the LED ::)
Title: Re: Mudbunny (green russian 1st build) - Pedal works but LED doesn't light
Post by: jimilee on August 01, 2013, 11:43:17 PM
Make sure the leads aren't shorting against the enclosure too.
Title: Re: Mudbunny (green russian 1st build) - Pedal works but LED doesn't light
Post by: decsnspace on August 04, 2013, 01:26:56 PM
After a lot of scratching  my head and troubleshooting I finally found the issue. It was a bad solder joint on the ground connection between the input jack and the 3dpt switch. Must have completely overlooked that connection when doing continuity checks. I re-flowed the solder joint and now the LED works perfect!  :D