TU-56 capacitor repair (part numbers)

Tony wrote: Assuming the capacitance and voltage ratings are the same, that would probably be true unless the circuit required a minimum or maximum ESR. Electrolytic capacitors generally have a much higher ESR than non-electrolytic types, though there are some new (expensive) low-ESR electrolytics. Most of the time it is OK to replace a capacitor with one that has lower ESR. An example where that is not true is filter capacitors on low-dropout (LDO) linear voltage regulators; LDOs have both minimum and maximum ESR requirements for the output filter capacitor, and in some cases the input filter as well, and exhibit oscillation and other instabilities outside the specified ESR range. That's why I still prefer normal (non-LDO) linear regulators wherever LDO is not required. Typically where moderately high capacitance is required with low ESR, solid tantalum capacitors are used, however there are some potential problems with tantalums so they are best avoided when not necessary. (And they are relatively expensive.) Tantalum capacitors will fail in a particularly spectacular fashion if reverse-biased. One day when we arrived at work, there was a 3/4-inch hole burned through our multi-thousand-dollar prototype PCB, and a charred spot on the workbench below it. Although there was not enough evidence left to prove it, we believe that a tantalum capacitor had been installed backwards. Eric