Play5 Gen.1 high temperature (55 degrees) on Capacitors

Why did you replace the capacitors?

Hi buzz,

thanks for your question.

They were all lifting their heads, and had only have of their capacity.

What do you mean by “lifting their heads”? And do you mean “half of their capacity”?

Hi 106rallye,

they were just bulged and i could measure around 300-400 uF only.

the two on the backside of the coils, i changed as well.

You obviously have some instruments. Have you measured the voltage and ripple?

​@106rallye: “Electrolytic” capacitors are two long layers of aluminum foil separated by a thin layer of insulating paste. The assembly is sealed in an aluminum can. A common failure mode is for the paste to vaporize and create pressure inside the sealed can. Typically these are cylinders with one flat end that is deliberately weakened so that the vapor can safely leak out rather than exploding the can. As the pressure builds, the flat end of the can will visibly bulge as the seal breaks. It’s often easy to spot bad capacitors by looking for bulges. As vapor escapes, the paste degrades, capacitance decreases, and short circuits can develop.

Modern, good quality Electrolytic capacitors in a properly designed circuit can last 20 years or more. A gradual decrease in capacitance is typical — but this does not result in the bulge. The bulge indicates that the capacitor was damaged by external causes. This could be poor circuit design or failure of another component.

ok, so the DC voltage measured on the capacitors is about 25V and the AC part measured with an oscilloscope is at 0,3V. I think that is what you mean by ripple voltage ?

Yes, “ripple” is the AC component. What is the frequency? I don’t know how these capacitors are used, but 0.3V seems odd to me. Does it vary with the audio signal? Do you hear any noise or see any ripple at the speakers? At zero Volume, I expect very low output. Since this is a switching amplifier I expect that there is a little high frequency ‘trash’ at the output.

No clue about your specific issue but many electrolitic capacitor failures are a result of an upstream issue which subjects them to too much ripple vooltage and current causing the overheating. Things like a failed diode in a rectifier.

Hi buzz,

the ripple does not change.

I attached a picture of the oscilloscope Display 

I can hear no noise at the speaker. Even at zero volume everything is fine.

problem is, that there is no schematic available for this Sonos Play 5.