Korg AJ,
As a music store owner let me tell you how this should be handled. When a customer has a problem with a keyboard and it's relatively new, I have the authority by Yamaha to replace the keyboard. If the keyboard has been brought to a authorized service center and it is not fixed in a reasonable amount of time, I would tell my customer to call me up and get me involved in the process. I would then call Yamaha service in Buena Park and talk to the head of service who would aolmost always ask for the keyboard to be returned to them. Yamaha then will issue me a call tag to pick it up from my store and it goes back to Yamaha for a credit to my account. An advanced replacement will go out to me to give it to my customer if I haven't already given him a new one from my stock. Before a customer gets frustrated, I always want to be involved. Yamaha service is really reasonable to deal with in situations where parts are taking to long or sometimes, the service provider is just so backed up that they haven't really even gotton to the keyboard at all.
George Kaye
Kaye's Music Scene
Reseda. California