DR-670: 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 down the REC and STOP/CONT buttons.
2. Press ENTER. You will get an "OK?" message confirming that you can proceed with the reset.
3. Press ENTER once more. "DONE" appears in the display once the Factory Reset has been completed.