I have report of a circuit board failure. The board was 20+ years old, and included at least one electrolytic capacitor. That capacitor would then be beyond its expected useful life. The board was still functioning, until the moment someone moved the panel the board was attached to. At that point, the board immediately failed, and has not recovered. Component-level failure analysis is not possible in this situation.

It occurs to me that the electrolyte in the capacitors is liquid, and thus subject to motion, perhaps moreso if the capacitor is partly dried out. So if an electrolytic capacitor is old enough that it should be considered end-of-life, but is still functioning and energized, is it possible that moving the energized capacitor would precipitate its failure?

  • 1
    \$\begingroup\$ What makes you think it was a capacitor that failed? It could have been any component that was jolted or bumped when it was moved. \$\endgroup\$
    – DKNguyen
    Jan 13 '20 at 20:38
  • \$\begingroup\$ I'm just exploring hypotheses. Could be the capacitor, could be something else. \$\endgroup\$ Jan 13 '20 at 20:40
  • 4
    \$\begingroup\$ Liquid filled? Not likely. The electrolyte is a paste, very thin between two sheets of foil. It is not moving around. \$\endgroup\$
    – Aaron
    Jan 13 '20 at 21:19

It's very unlikely that an electrolytic capacitor failed as result of being moved. They generally either degrade gradually as the electrolyte dries out (greatly accelerated by high temperature) or they fail catastrophically and vent or bulge, particularly when abused or badly made.

Much more likely is some kind of mechanical damage, a solder joint or PCB cracking or a connection becoming dislodged. If it's an unpackaged board, the possibilities of mechanical damage are much greater- from missing configuration jumpers to surface-mount components completely sheared off.

And if the board is not enclosed (sometimes even if it is) there is the possibility of ESD damage, especially at this time of year in the Northern Hemisphere when humidity levels tend to be low.

  • \$\begingroup\$ I'll add that electrolytic capacitors have a shelf-life of under 5 years, according to the manufacturers. 20 years is a very long time for an electrolytic. \$\endgroup\$
    – rdtsc
    Jan 13 '20 at 21:46
  • \$\begingroup\$ Just to clarify, that shelf life is for de-energized capacitors. Charged capacitors will last longer, though 20 years is still a very long time. The longest I've seen any manufacturer allow for is 15 years. \$\endgroup\$ Jan 15 '20 at 12:47

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