Electrolytic capacitors- ESR and DMM, or something else needed, too?

mikey122

New Member
Hello. As i started my journey on repairing these machines from 70s and 80s i noticed some problems which could lead to bad electrolytic cap. However, ESR and capacitance measured good. On some caps capacitance on DMM is actually almost twice uF than rated. Does this means cap could be bad or cap is only bad when capacitance on DMM is very low?
Was ESR and capacitance always enough for you or you measured leakage, too?
 

thinkchronicity

Member (SA)
Twice the rated capacitance certainly means the cap is bad due to d.c. leakage - which is the true test of capacitor life. Your DMM interprets that as a cap taking a long time to charge....must have high capacity...but no, it's a false reading.
I just changed six perfectly good caps in the audio path that measured highish for uF and ok for esr, but with new ones installed the left/right balance came good. Was way off before.