In order to hard reset a Maxon MX-7990, you should perform the following steps.

Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Maxon MX-7990 device will be brought back to the default configuration of a brand new device.

1. For starters, turn on the device.
2. Press the Call button in order to open the dialer.

3. Enter this sequence into the dialer: either *#77218114# or *#9426*357# or *#118811# or *#3646633#
4. To complete the hard reset process, press the Call button. Wait for your device to reset and restart.