Do power supply capacitors wear out?

do power supply capacitors wear out over time?

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Reply to bsurkein

bsurkein wrote :

do power supply capacitors wear out over time?

http://en.wikipedia.org/wiki/Capacitor

Quote :

Capacitors may catastrophically fail when subjected to voltages or currents beyond their rating, or as they reach their normal end of life. Dielectric or metal interconnection failures may create arcing that vaporizes the dielectric fluid, resulting in case bulging, rupture, or even an explosion. Capacitors used in RF or sustained high-current applications can overheat, especially in the center of the capacitor rolls. Capacitors used within high-energy capacitor banks can violently explode when a short in one capacitor causes sudden dumping of energy stored in the rest of the bank into the failing unit. High voltage vacuum capacitors can generate soft X-rays even during normal operation. Proper containment, fusing, and preventive maintenance can help to minimize these hazards.
High-voltage capacitors can benefit from a pre-charge to limit in-rush currents at power-up of high voltage direct current (HVDC) circuits. This will extend the life of the component and may mitigate high-voltage hazards.

Message quoted 1 times

Reply to rexter

rexter wrote :

http://en.wikipedia.org/wiki/Capacitor

Quote :

Capacitors may catastrophically fail when subjected to voltages or currents beyond their rating, or as they reach their normal end of life. Dielectric or metal interconnection failures may create arcing that vaporizes the dielectric fluid, resulting in case bulging, rupture, or even an explosion. Capacitors used in RF or sustained high-current applications can overheat, especially in the center of the capacitor rolls. Capacitors used within high-energy capacitor banks can violently explode when a short in one capacitor causes sudden dumping of energy stored in the rest of the bank into the failing unit. High voltage vacuum capacitors can generate soft X-rays even during normal operation. Proper containment, fusing, and preventive maintenance can help to minimize these hazards.
High-voltage capacitors can benefit from a pre-charge to limit in-rush currents at power-up of high voltage direct current (HVDC) circuits. This will extend the life of the component and may mitigate high-voltage hazards.

What is considered the "normal end of life" for a power supply capacitor? I recently was in audio/electronics store looking for a new A/V receiver to replace my >10 year old stereo receiver. I mentioned to the store person that I thought my old receiver was starting to sound a little ragged, and he replied that the power supply capacitors were wearing out. Could he be correct? Do power supply capacitors have a finite life expectancy?

Reply to bsurkein

Did he open up your receiver? If not then he is just speculating. If you don't use your unit all the time and unplug it if not use then he might be right, but i would check the terminal port first if it's dirty, means no loss contact. Second is to check the volume. If all these are ok then have it check by electronic audio technician to make sure it's not the power transistors/IC.

Reply to rexter

Electrolytic capacitors which are used in power supplies and other circuits can, due to age, no longer measure at their correct values and will cause hum if in power supplies. They can also balloon out which means they are damaged and need to be replaced. The higher the operating voltage the more likely that his can happen. It is also common for manufacturers to use just exactly the voltage that the cap will see rather than leaving a 20-50% over-voltage capability for safety and longevity. Many flat screen TV power supplies fall due to this.
If you have replaced the original speakers that you got when you bought the receiver this may have made an inherent flaw in the receiver noticeable where the original ones did not.

Reply to americanaudiophile

non-plague capacitors should give many years of trouble free performance.
http://en.wikipedia.org/wiki/Capacitor_plague
ripple "hum" will be the most pronounced characteristic of dry/failed capacitors in older analog amplifiers.

Reply to captain8ball

Does aging occur? Yes, all components age.

Is it as big of a problem as everyone seems to think? No, I don't think so.

My comments on capacitor aging:
http://www.tomshardware.co.uk/foru [...] itor-aging

Reply to jsc

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