Empirical Experience: Good and Bad Electrolytic Capacitors

[Jim]

I'd heard of motherboards dying because of bad electrolytic 
capacitors (caps), that the bad caps had a bulged top, 
often showing signs of leakage.  

I just measured some caps salvaged from dead motherboards.  
Many of the caps were bad, with only a few percent to about 
twenty percent of their nominal value.  A couple had half 
of their nominal value.  All of the bad caps had bulged 
tops.  All of the good caps had flat tops.  

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If you have a dead motherboard with caps that have bulged caps, 
you _might_ be able to fix the motherboard by replacing the caps.  
Keep in mind that many of the caps, especially by the CPU, 
are special.  They have very low resistance.  

Of course, there are many ways for a motherboard to die, 
so if you replace bulged caps on a dead motherboard, 
you might have good caps on a still dead motherboard.