Accidental Reversed polarity killed RNGD & Spotted Dick - Looking for help

[jgoldkamp]

1.What does it do, not do, and sound like? It does not work at all, but passes signal when bypassed

2.Name of the circuit = RNGD and Spotted Dick

3.Source of the circuit (URL of schematic or project) =
https://effectslayouts.com/wp-content/uploads/2019/11/RNGD-Build-Doc.pdf
https://effectslayouts.com/wp-content/uploads/2019/08/Spotted-Dick-Build-Doc.pdf

4.Any modifications to the circuit? No

5.Any parts substitutions? N

6.Positive ground to negative ground conversion? Not on purpose

7.Turn your meter on, set it to the 10V or 20V scale. Remove the battery from the battery clip. Probe the battery terminals with the meter leads before putting it in the clip. What is the out of circuit battery voltage? => No battery used

Now insert the battery into the clip. If your effect is wired so that a plug must be in the input or output jack to turn the battery power on, insert one end of a cord into that jack. Connect the negative/black meter lead to signal ground by clipping the negative/black lead to the outer sleeve of the input or output jack, whichever does not have a plug in it. With the negative lead on signal ground, measure the following: I already disconnected the power.

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Hi All,

I accidentally reversed polarity killed my RNGD & Spotted Dick pedals. Besides looking for help on these two pedals, what do you trace back to when you accidentally reverse polarity on a whole circuit? When you reverse the polarity on a capacitor? When can you stop tracing back and forwards?

[idy]

Both of those should have a series reverse polarity protection diode, 1n5817, that should have prevented damage.
(Although the RNGD schematic only shows a battery, no power jack.)
Stomp boxes usually have a diode like that (or "shunted" across the DC input) that may burn out, as in reverse polarity it is shorted across a power supply. That could also kill a supply that does not have internal protection.

Check if those diodes are OK. Check if your supply is still working.
After that I would check electrolytic caps and ICs and transistors.

[jgoldkamp]

Thank you for confirming that. I thought that was the case by the schematic, but wasn't certain.

But what about in cases where there is "magic smoke." What are first steps in that situation?

[antonis]

But what about in cases where there is "magic smoke."

Do not inhale it..

[GGBB]

Thank you for confirming that. I thought that was the case by the schematic, but wasn't certain.

But what about in cases where there is "magic smoke." What are first steps in that situation?

#1 - visually inspect for burnt/exploded/damaged components.

[GibsonGM]

Thank you for confirming that. I thought that was the case by the schematic, but wasn't certain.

But what about in cases where there is "magic smoke." What are first steps in that situation?

As was said before - the ICs, transistors and electrolytic caps in the power supply path are probably fried.  You change them until the FX works...

[ElectricDruid]

I'd start by replacing anything that is obviously toasted, and then after that, I'd get the audio probe out and go through each pedal from the input through to the output and see how far I could get. Each time you find something dead, you fix it and then see if you can't get a little bit further.

Typically, the damage isn't as bad as you think - at least, that's been my experience. Or maybe I'm just very pessimistic to start with!  It only takes one thing to be totally dead for "no sound" to be the result, so if you can find that one thing and fix it, you might get lucky and there might not be anything else.

HTH

[PRR]

there is "magic smoke." What are first step

First step is RIGHT AWAY look and see where the smoke is coming from (but don't get shrapnel in your face!). Any clue may help: 'R17!' or 'farleft corner'. Next use your nose. The stink will be worse right AT the smoked part, less further out. By tomorrow (even in an hour) the whole board or room will smell of smoke, so be quick. Finger may help find the hot part.

OTOH don't be snorting e-smoke like it was the finest weed from Tommy Chong, it's probably bad for you. (Everything is.) Phenol is the base of many electronic parts. AFAIK short-term exposure is irritating, not sickening; but there are many phenols and I am not a chemist or toxicologist.

[duck_arse]

I accidentally reversed polarity killed my RNGD & Spotted Dick pedals

how did you accidentally reverse?

But what about in cases where there is "magic smoke."

magic fire extinguisher.