ME-50B, ME-50: Initializing - Restoring the Factory Settings
The following procedure can be used to clear the internal memory and reload the factory settings:
(CAUTION: All USER information will be lost. Be sure to back up any information you wish to keep.)
1. Power on while holding BANK < and WRITE. "F" will appear in the display.
2. Press WRITE twice.
Note: Never turn off the power while the Factory Reset is in progress.