GE JES1634 Owner's Manual page 28

About the other features.
CLEAR
OFF
SOUND
28
Child Lock-Out
You may lock the control panel to prevent the microwave
from being accidentally started or used by children.
To lock or unlock the controls, press and hold CLEAR/OFF
for about three seconds. When the control panel is
locked, an L will be displayed.
Sound
Press SOUND to turn the oven beeper on or off.