L.G.
First off, have you talked to the "Genius Bar" at an Apple store? If it is an easy fix, they can help you there on the spot. If the iMac needs to be worked on I would recommend ClickAway in Campbell. I have also heard of 1-800-wefixmacs. I do NOT recommend the repair place up on Stevens Creek. We took our PowerBook there and did not get a good feeling about them, and have since heard bad things about their reputation. Good luck!