I have a MESR-100 ESR meter and have the same issue. It is designed to test capacitors on the board/incircuit and works for many of those I've tested. However, I have board with two 0.47uF, 50v electrolytic capacitors and get an overflow message when testing. They have been discharged. Since this meter goes to zero on a direct short (clipping the leads together), can I properly assume there is no resistance in the capacitor for some reason?