From: jjhudak4@gmail.com   
      
   On Thursday, July 6, 2023 at 11:51:06 AM UTC-4, Dan Green wrote:   
   > Hi all,    
   >    
   > Is it advisable to change old electrolytics which are reading a    
   > capacitance considerably higher than their stated value? I know they    
   > vary a lot anyway, but if I have say a 480uF cap which is reading    
   > 640uF, should that be a concern? Does it indicate some underlying    
   > issue with the cap?   
      
   Yes, higher values indicate a leakage issue.  IMHO, capacitor measurement   
   reading should be taken with a grain of salt.     
   Where they occur in the ckt needs to be taken into consideration as well as   
   the age and type of cap.  The most often cited usage is in power supplies   
   (both linear and SMPS).  As a general rule of thumb, for me, if it is a linear   
   PS, over  20 yo, and    
   there are PS behaviors that suggest a capacitor issue, replace all the   
   electrolytics  with equivalent capacitance and slightly higher WVDC if   
   possible.  Not worth revisiting that repair later down the road.  If one comes   
   across a dead SMPS and it is a    
   capacitor issue, replace them all.  It is not worth saving 50 cents just to   
   rebuild it later.     
   I believe a better measurement approach to diagnosing bad caps is a capacitor   
   checker in conjunction with an ESR meter.   
   As I mentioned, these are my guidelines/approaches.  I am sure other ppl have   
   theirs and may disagree with me.  I'll just say to each their own.   
   Good luck   
      
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