In order to hard reset a Philips 392, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Philips 392 device will be brought back to the default configuration of a brand new device.
1. Turn on the phone.
2. Press the Call button to open the dialer. Type in this code: #20021208# or *01763*737381#.
3. Press the Call button again to confirm the hard reset process. Voila! Your phone will now reset and restart. Done.