actually there is a way to test a capacitor i have a capacitor meter which read the value which is stamped on the side of the capacitor. Also they can be tested under load and to see if they are breaking down under voltage , but must be removed from the circuit to do the voltage test, I have the test equipment which apply a DC voltage and an electric tube EYE which shows closed if the capacitor actually shorted, works very well and i believe it was made by PACO test equipment company
I can supply a picture if you need one, I don't believe they make them anymore though, but you never know.!
Alan Mancus
Interesting about the electric eye. They were used for radios as a tuning aid and much else. They measured the value of a negative voltage applied to a "grid". The greater the voltage, the more they fluoresced and closed the eye circle. I guess the voltage applied to the eye was probably inversely proportional to the leakage current thru the capacitor...depending on what was designated as "OK".
