Vintage Synth Repair

Hey techs,

I went through the US Air Force electronics school about 17 years ago, and thought I was doing pretty well, but recently I was going through some schematics for my vintage gear and found myself lacking in some areas.  I really feel the need to brush up on my electronics fundamentals.  Does anyone on the list here know of some sites on the internet that can walk you through some of the fundamentals?

Any help would be appreciated.

Rob
Portland Oregon