Hola, buenas noches.
Prueba esto:
SY77 Factory Reset procedure
WARNING: All user stored data will be deleted. If the current settings and data are not expendable, create a backup before executing the Factory Reset.
1) Turn the power on.
2) While pressing the [VOICE] button, press and hold the [BANK D] button, then the [8] button. The SY77 will run the INITIAL TEST routine and display the Test Program Menu.
3) Press the [COPY] button. The SY77 will execute Test 48 'Factory Settings', automatically exit the test mode, and then return to play mode.
Espero que te sirva.
Un saludo.
Mateo.