Does this electrolytic capacitor need replacing?

[edbarx]

The capacitor became warm on power supply powering. This implies a larger than normal leakage current. The temperature did not continue to rise afterwards. Should I replace the capacitor?

 

[Maserito]

This implies a larger than normal leakage current.

For the switched mode power supplies it is pretty normal and caused by high ripple current. If your PSU is transformer based and the filter capacitor (the one after the rectifier) become warm when no load is applied - this could be a leak, take it out and measure.

 

[edbarx]

This is an iron cored transformer based power supply. At 100Hz the electrolytic capacitor should not become warm.

 

[Maserito]

You are right, it could be faulty. If it's a cheap one or you have the spare just replace it.

 

[anatech]

Has the capacitor sat for years in storage? It would get warm during oxide layer reforming. That may have damaged it. You would always current limit when bringing up equipment that was in storage, or older NOS capacitors.

I'll assume the circuit wasn't drawing over normal or you would have mentioned the hum from the transformer. Without some specifics, it is hard to give you a good answer.

 

[edbarx]

I am of the opinion that it is better to replace the capacitor. The capacitor is the smoothing capacitor of the power supply powering a boombox with detachable speakers. From what I learnt on this forum and similar forums, it is advisable to replace the capacitor. I estimate it is about 30 to 40 years old.

I asked to have a second opinion.
Thanks.

 

[anatech]

Hi Ed,
Okay, that really helps with situational awareness. Now we have a good idea of what you are dealing with.

Those are cheap, by all means replace it. Go for a replacement with the same lead spacing. Those cost more, and there is a good reason for it. Increasing the voltage rating is better than increasing capacitance.