repair shop in Philadelphia

Can anyone recommend a repair shop around Philly. I have a Linn tuner that doesn't get a signal. Linn says that they don't repair this unit anymore. They said it's probably related to a circuit board, so they sent me the service documentation on the tuner and suggested I bring the tuner and info to a repair shop and that could take care of it. But I don't know first hand of any places around the city.
Thanks