I have not opened one either. Then there are also oil filled capacitors, but they are generally lower value but much higher voltage ratings for very high voltage supplies (think kilovolts). They are typically square cans. I have not opened one of those either.
Joined: Jan Thu 01, 1970 1:00 am Posts: 12208 Location: Somers, CT
Usually the rubber seal beneath the vent cap deteriorates over the decades, and those caps are dried out by the time we get them. Or, a poor service inverts the chassis, and finds them piddling all over the bench! It was a borax solution, which is relatively harmless.
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