Clears the contents of Bookkeeping. When clearing, use the
Service button to bring the arrow to YES (Clear) and press the
Test button. When the data has been cleared, COMPLETED will be
displayed. Press the Test Button to return to the Menu mode.
Bring the arrow to NO (Cancel) and press the Test button to return
to the Menu mode without clearing the data.
Also, note that the game setting contents are not affected by
Backup Data Clear operation.