Symptoms of fried capacitors or resistors?

[80k]

Oftentimes when building a pedal, there will be a component that i am having a hard time soldering and i am concerned that i fried it... so i make a mental note of it, and if something doesn't work later, i'd probably try replacing it or something.

So far, i've been pretty lucky, but it led me to wonder what exactly happens when a capacitor or resistor gets too much heat.  Would it just drift in value, but still "work"?  Like what if i overheated a capacitor... would it cease working and make my pedal unuseable, or would it still work but make a lot of noise, or would it still be a totally working capacitor but at a different value (and hence hard for me to know)?

Just curious about what it means to fry caps and resistors, since i usually only hear much about overheating transistors and opamps (to the point where they don't work).

[R.G.]

Given the prices of resistors, caps and opamps, why don't you deliberately fry some, then listen and measure?

[aron]

Maybe the capacitor would drift, but I'm not sure. I know the feeling; when you are a beginner you apply too much heat for too long.

That being said, I don't think I have ever wiped out a capacitor or resistor. Those things are tough!

I would continute to improve my soldering and move on and not worry about these components.

[80k]

cool i might just fry some on purpose and check it out  just a bit curious what a fried capacitor is like... so far i've been pretty lucky with my pedals, as i haven't fried anything yet!

[Paul Perry (Frostwave)]

It's prety hard to damage a resistor with a mere soldering iron. But if you manage it... the end might fall off. That's the usual failure mode. The old carbon comps used to shift in value (permanently).
As for caps, electrolytics are OK until they burst. I havn't seen one burst thru soldering, but if you reverse them, they can heat up & burst.
Polystyrene caps have a low breakdown temp, the polystyrene melts & (I expect) shorts.
But, ther eis no danger of hurting any component with a soldering iron, if the iron is at the right tip & everythign is clean. Damage comes when the iron is not hot enough, or when tarnishing prevents the solder flowing onto the component, and peopel hold the iron there for 15 nminutes trying to get it to 'work'. :roll:

[aron]

Speaking of that.... what is the best way to get solder to stick to the back of alpha pots? I used flux and high heat but.... wow.... it needed a lot!

[Fret Wire]

Speaking of that.... what is the best way to get solder to stick to the back of alpha pots? I used flux and high heat but.... wow.... it needed a lot!

It's the plating, some of the CTS guitar pots were notorious for that. Take a little piece of sandpaper and scuff up the area (or whole back of pot) you want to solder. Then it will stick. I've also done it with a metal wire brush on my Dremel.

[ExpAnonColin]

I can get mine to stick, no flux, with just sand paper.

-Colin

[80k]

what are you guys soldering to the back of the pots?

[Paul Perry (Frostwave)]

what are you guys soldering to the back of the pots?

The shield on shielded wire, for low level audio signals threatening to pick up hum. When the pot itself isn't earthed. As in a guitar.

[80k]

what are you guys soldering to the back of the pots?

The shield on shielded wire, for low level audio signals threatening to pick up hum. When the pot itself isn't earthed. As in a guitar.

ah ok, thanks for the clarification!

[aron]

That's right. Sandpaper. Now I remember. I have a new dremel so I will try that next time.

Thanks!