PC Method [Backup]

If you have a PC: Reboot to recovery, connect your phone to your PC with USB cord, launch cmd/terminal on your PC, make sure you have adb and device driver (if using Windows) installed, then on your PC issue these two command lines:

type "adb shell" then hit enter

dd if=/dev/block/bootdevice/by-name/persist of=/sdcard/persist_backup.img