Capacitor Failure Symptoms: Difference between revisions
Rewrite with full citations (Nichicon CAT.8101H hosted here, Vishay 40110, KEMET F3011): corrected 60 Hz hum to twice mains frequency, corrected bulging mechanism to Nichicon gas generation, added missing film/X2 suppression section, added tantalum derating 60-50 percent, added Class II ceramic DC-bias behaviour, replaced Japanese-brand rule with no-datasheet-no-purchase, replaced IPA-only cleanup with Nichicon soap-and-water plus never acidic/alkaline, replaced reforming folklore with Nichic... |
Remove self-referential wording per house rule |
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== Replacing capacitors == | == Replacing capacitors == | ||
* '''Voltage rating: match or exceed the original.''' A rating at or below the rail the part sits on is always wrong | * '''Voltage rating: match or exceed the original.''' A rating at or below the rail the part sits on is always wrong, and it damages machines. | ||
* '''105 °C parts in power supplies.''' Life follows the Arrhenius relationship — Nichicon states that life doubles for every 10 °C drop in temperature.<ref name="nichicon" /> A 105 °C part in place of an 85 °C part of the same endurance rating is a real, calculable gain, not a superstition. | * '''105 °C parts in power supplies.''' Life follows the Arrhenius relationship — Nichicon states that life doubles for every 10 °C drop in temperature.<ref name="nichicon" /> A 105 °C part in place of an 85 °C part of the same endurance rating is a real, calculable gain, not a superstition. | ||
* '''Match ESR and ripple rating, not just µF and volts.''' A switch-mode supply designed around a low-ESR part will misbehave with a general-purpose one. Exceeding the ripple rating is one of Nichicon's listed causes of capacitance loss and rising ESR.<ref name="nichicon" /> | * '''Match ESR and ripple rating, not just µF and volts.''' A switch-mode supply designed around a low-ESR part will misbehave with a general-purpose one. Exceeding the ripple rating is one of Nichicon's listed causes of capacitance loss and rising ESR.<ref name="nichicon" /> | ||