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Old 01-19-2009, 02:15 PM
Dionysius Dionysius is offline
Dionysius
 
Join Date: Jan 2006
Location: Seattle WA
Posts: 261
Quote:
Originally Posted by lowriderdog37 View Post
Dionysius, I got to thinking about this, if the capacitors are the shortfall, why shouldn't we just replace them all? Or better yet, if if just one is consistently failing, could it be because of something else? I haven't looked at one for a while, but most if not all of the capacitors are identical thought the amp, so if only 1 is failing, it could be because of something else making it fail.
Electrolytic capacitors will fail with age - they are prone to a leakage failure mode effect. When people claim they 'fixed' the board by soldering every land what they have really done is just touched the electrolytic lands with a hot iron and rejuvenated them with heat shock but this is a temporary fix IMHO. These caps were manufactured circa 30 years ago in a process inferior to what we would have today. You may find that not all have failed but my posit is the heavy hitter one which serves as the 'memory' in this ancient analog design is the one that is giving the major symptom. This circuit can be restored to its original and very fine original functionality. I admire you for looking at this and I will help where I can. The other caps act as filters (I am having to make assumptions here since I have no schematic) and their failure or partial failure could cause hunting and weird secondary effects. Note that these caps are polarity sensitive. And yes, you should replace all of the electrolytics. The other components are probably ok.
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