Got a question about the need for cleaning and lubricating inside my Yamaha receiver. The Best Buy sales guy talked me into getting a service agreement that includes a cleaning(and lube) once a year. Is this necessary(mainly the lube part, I know it probably should cleaned more than just dusting)? I really do not want to unhook everything and get this so called cleaning and lube done??? Does anyone else have this done or is this a DIY thing?? Thanks for any advice and/or input on this.