Briefly reverse-biased electrolytic capacitor, no visible damage. Replace?

Help Support GroupDIY:


Well-known member
Dec 27, 2010
Subject tells the story--

Accidentally installed my bridge rectifier diodes in reverse orientation due to some faulty PCB silkscreening (my fault) in a simple linear regulated 15v bipolar power supply.

It was only for a few seconds, but long enough to make the voltage regulators start smoking (I immediately killed power)

The capacitors don't show any sign of having gotten hot or damaged, but they did receive reverse voltage for a few seconds.

The question is--should I order new 2200µF and 100µF (input and output) filter capacitors, or is it most likely that they survived?

I know the easy answer is "might as well just order them," but I have everything else on hand already, so it would require making a special order. I used over-spec'd 100v caps, if that makes any difference.

Thanks for any insight!

Bo Deadly

Well-known member
Dec 22, 2015
New Jersey, USA
If it were me I would definitely change them because if you don't and there's some other problem you'll wonder if it was the reversed caps. I have a mic pre were I accidentally reverse polarity on the amp board and I used it anyway and now I always wonder if it's working as well as it could. Save yourself the trouble and fix it now.