Before you give your handset to repair shop or buy new handset, please try the following procedure to repair your device. First charge your battery more then 70%, backup your important data like phone-book, message, email, images and settings and in most cases take out SIM card and SD card. After doing hard reset not possible to recover your data, so online backup is always important. For all of your data, a backup should be done on a external device, hard drive, raid system media or SD card.
How to Hard Reset Samsung Galaxy S II
Reset Via Setting
- On the Settings screen, touch Privacy > Factory data reset.
- When prompted, touch Reset phone, and then touch Erase everything. The mobile phone resets the settings to the original factory settings, and then restarts
- Switch off your device.
- When your phone is switched off, press together Volume Up + Home button + Power button.
- If you see the menu in your screen, choose with Volume buttons "wipe data/factory reset" and select with Power button.
- Next confirm the operation by Power button.
- Then in the menu select reboot.
- Now wait until phone restarts.
Reset Via Master key
- Start by turning your device on, to do it press Power button.
- Then dialling screen of your device type this code in dialer: *2767*3855#
- Next on confirm whole Factory reset process by tapping Call key again.
- Now your phone should reboot.