7 Oct
2010
7 Oct
'10
3:23 p.m.
I thought that when the seal failed, the electrolyte
dried out?
Either way spells bad news. Bad seals, however, can happen to any type
of capacitor. When I was looking at Claude's B205 mainframe in hopes
to resurrect it, it became quickly apparent that nearly every
capacitor in the thing (I estimated 6000) needed replacement, because
Burroughs used those old Sprague "bumblebees". Many of the capacitors
were so bad you could see cracks in the plastic. Moisture + paper +
high voltage.
I fully expect that all of those capacitors will fail
eventually, but there
isn't nearly enough data to predict a mean lifetime.
I bet there is a truckload of electrolytic capacitor failure data in
certain archives. The military has been seriously studying component
failure ever since World War 2. We have found the studies for tube
failures in computers and electronics, and they really tell all, but
not one for capacitor life (partly because there are not many hardcore
old capacitor geeks out there).
--
Will