Possible diode fault?

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Possible diode fault?

chuckflorist
Hello,

Wondering if someone had any ideas with this (for a N00b!)

Have just built a Ram's head 73 Big Muff from a kit which i'm having troubles with i.e. no output. I've been checking the voltages at certain points but don't seem to be getting voltages in some areas and very low voltages elsewhere.

The only voltage I have on the board over 1v is the supply from the 9v (@-8.91). The voltage after the Dx is -0.12 I'm still learning about diodes but does that sound like the diode is inhibiting the current flow / stuck? The diode is an 1N5817.

Any assistance would be much appreciated on my upward struggle on the learning curve!

Cheers Chuck
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Re: Possible diode fault?

induction
Do you have a schematic you can post or link to. Pictures of your build would also help.

Sounds like your diode might be backwards, but I can't say for sure without a schematic at least.
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Re: Possible diode fault?

chuckflorist
Hello,

Thanks for taking the time to reply.

The layout is here:
http://tagboardeffects.blogspot.co.uk/2012/06/ehx-73-rams-head-big-muff.html

Here is the top shot of the board (I believe the diode is the correct way):
http://i938.photobucket.com/albums/ad221/chuckflorist/20131008_190645_zps9c501af3.jpg

And here's the bottom:
http://i938.photobucket.com/albums/ad221/chuckflorist/20131008_190741_zpsd9cd6a34.jpg

I have gone through the gaps in the strips with a small hacksaw to remove any solder bridges as I am still very much a novice.

Chuck.
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Re: Possible diode fault?

induction
That diode should drop less than 0.5V. If you're getting near 0 after that diode, then it's probably faulty. I'd replace it. You can easily check whether this is the case, even if you don't have a replacement. That diode is nothing but polarity protection, the circuit does not require it. Remove the 9V wire and move it down 2 rows to the other side of the diode. If the circuit works, the diode is bad. Replace it. (If you don't have one on hand, you can use the circuit without the diode as long as you avoid reversing the polarity of the power supply.)

If this doesn't fix it, we'll keep looking.
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Re: Possible diode fault?

chuckflorist
Wow, works like a dream! Thanks very much :-) I guess it was the diode.