Will reverse polarity destroy caps and transistors?

[gutsofgold]

Say I accidentally plugged a DC adapter into a pedal and the adapter was outer ring negative center positive and the pedal was wired to accept opposite that. What will happen? The pedal doesn't work should I replace all the polar caps and transistors?

[alanlan]

If you are sure it is damaged, might help to get a cct diagram to better pin-point those devices which may have taken the main brunt of the reverse polarity.  Have you tried it out with a battery connected?

Also, depends on how many components we're talking about.  If it's a handful and you've got spares then fair enough, don't waste time but if there are a lot and you are going to have to source new components, it's got to be worth trying to locate the fault before replacing everything in sight.

[darron]

you'd expect the pedal to have protection. ahh well.

capacitors can definitely blow from reverse polarity. transistors get less damaged i think, but they supposedly get worse sounding slowly over time from damage (again, i think). but i've never blown a transistor yet from stuffing around with them. caps yes though.

see if it has a protection diode that goes in parallel with the circuit. maybe that's blown and is shorting out if you are lucky. do an ohm test on both polls of the pedal and see if it's shorted.

[frokost]

R.G. wrote a post on this earlier: http://www.diystompboxes.com/smfforum/index.php?topic=55003.0

[Paul Perry (Frostwave)]

Which pedal was it?
Someone may have the circuit & then some idea as to what has happened.
With electrolytics, you often can get away with it for a bit.

If it was a commercial pedal, you may have shorted out a protection diode, who knows?
One thing that does usually fail immediately is op amps with reversed power. And tantalums are a bit fragile.

[petemoore]

With electrolytics, you often can get away with it for a bit.
  I was kind of hoping someone would say this first, thanks Paul...
  I've a running experiment which supports this, at least one...[lol]/
  The time it takes for the beeper to de-beep itself has nothing to do with it AFAIK...sometimes that thing'll beep a long enough time to make me thing there's a short in the PS, that'd be a large value Electro faking it for a short period.
  Someone wrote that a capacitor can short across ?
  That'd be easy enough to test for..I'm pretty sure I've never read short across cap before.

[dschwartz]

what do you think about this...
and forget about reversed polarity..

[darron]

what do you think about this...
and forget about reversed polarity..

i've actually always wondered why that wouldn't work... i'll be interested to see what people say about it. looks good.

[dschwartz]

if you look close.. you will see that´s a simple rectifier bridge!

[Paul Perry (Frostwave)]

The only problem with the bridge, is that you lose two diode drops worth of voltage.
Which probably doesn't matter.

[dschwartz]

specially when you use unregulated PS..those give live 12 volts DC unloaded, so probably won´t make a difference  there..
if you  use only YOUR regulated PS or batteries, is not worth to use this circuit..

[jimbob]

I thought Fultone had something like that in his pedals where it didnt matter what u plug in.