When you need to check capacitors on a pcb do you use an ESR meter that can test with them in the circuit or do you lift one leg or even remove them completely to do your tests. I have been contemplating maybe getting an ESR meter, but not really sure how consistently accurate they are when doing tests with the caps still in place on the board.

TKX

I have seen and changed dozens of open electrolytics and probably a few shorted ones. I don't think I've ever even conceived of trying to measure the ESR or ESL of one. Wouldn't that be a physical property, unlikely to change unless the cap has sustained visible damage. The puffed up caps on Dell motherboards probably have the same ESR as the normal ones. I do check for leakage though.
Joe

I'm not exactly sure yet how these differ from a standard stand-alone cap tester or multimeter with cap test function. Seems the better models of these things are generally a little too pricy for me right now, but I found a cheap ESR made by Blue that I may look into getting later on.