In order to hard reset a NEC DB4000, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
NEC DB4000 device will be brought back to the default configuration of a brand new device.
1. Hi. Please turn on the device.
2. After the phone turns on, press the Menu button.
3. Go to Settings Menu > Reset Settings. Enter the security code (default can be 0000 or 000000 or 1234).
4. Lastly, confirm the whole process. Well done.