High ESR capacitors
When electrolytic capacitors age, many changes can take place:
- drift in capacitance
- increase in ESR
- increase in leakage current
- open circuit
- short circuit
High ESR is a common problem. It is easy to test for this without removing the capacitor in question. Connect a good capacitor in parallel with the capacitor in question. If the problem goes away, the original capacitor is probably bad due to high ESR and/or reduced capacitance.
Modern electrolytic capacitors are available in a wide variety of ratings and shapes. Replacing old electrolytic capacitors with new ones is a straightforward procedure. Just make sure that the new one can fit, mechanically.