I agree with Mr Peabody that you ought to weigh the cost of repair vs. the cost and improved functionality of a new product. Very often today it simply isn't worthwhile to repair, (unfortunately).

Yamaha has a very good Support website where you might find authorized service centers, service manuals, and parts: see here ... Support - Yamaha United States. Don't forget that shipping could be part of the repair cost if there is no local repair depot.