Sure,myself and a thousand other folks all over the country knows a tech!! Where are you located?What problems are you having?Might be a simple fix that a member can help you with.Check out the following link to NAD authorized service centers.
http://www.techsourcedist.com/technical_bulletins/NAD%20Service%20Center%20Listing%207-NOV-07.pdf
http://www.techsourcedist.com/technical_bulletins/NAD%20Service%20Center%20Listing%207-NOV-07.pdf