Yamaha PORTATONE PSR-500M Owner's Manual page 46

УАМАНА
IMPORTANT
PLEASE RECORD THE SERIAL NUMBER OF YOUR UNIT IN THE
SPACE BELOW.
MODEL: PSR-500M
SERIAL NO:
THE SERIAL NUMBER IS LOCATED ON THE BOTTOM OF THE UNIT.
RETAIN THIS OWNER'S GUIDE IN A SAFE PLACE FOR FUTURE
REFERENCE.