My experience (chronicled here) was that the Internets were fantastic at diagnosing my problem. I ordered the replacement IC amps online, then when I extracted the board, it was clear that several resistors were fried. I found the service manual (free, on RapidShare or equivalent) to get the resistor values. All in all, not a bad experience, but I never would have gotten that far without the Internet to document how other people solved the very same problem.