In order to hard reset a Mitsubishi M430i/M900, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Mitsubishi M430i/M900 device will be brought back to the default configuration of a brand new device.
1. Hold down the Power/Call Off button until the phone turns on.
2. Enter in one of these sequences: *#94267357# or *#19912006# or *#3646633#
3. Done! Woohoo.