How to spot a failing capacitor
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CircuitScope · Added 05 Oct 2026 · 5 views
Bulged tops, leaks and high ESR — how to find and replace a bad cap.
Electrolytic capacitors are one of the most common failure points on any board. Learn to spot them before they take other parts with them.
Signs of a bad capacitor
- Bulging top — the scored top of the can is domed instead of flat.
- Leaking electrolyte — crusty brown/rusty residue around the base or on nearby pads.
- Popped or split vent, or a burnt smell.
- High ESR — measures with an ESR meter even when the cap looks fine.
Replacing it
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