Check out Console Concepts, now known as CCGaming.

www.ccgamingonline.com

Phone# 678 - 831 - 0690

2750 Jiles Rd Suite 111, Kennesaw, GA 30144

The guy who started Console Concepts figured out what was causing the Three rings of Death on the Xbox360 before Microsoft did.

They did a full restoration on a NES for me and customizing systems is their specialty. They know them all backwards and forwards. Sometimes though there just isn't a way to service the system outside of the manufacturer. They will let you know straight up if they can do it or not.