1st makeHard Reset your phone
Samsung I9300 Galaxy S3 Hard Reset Steps:
- Take out your phone's battery, SIM-card and memory card too.
- After 10 seconds put the battery back into your phone.
- Press and hold Volume Up key + Home key then press Power key.
- Keep pressing the above keys until Samsung logo appears,Then when you see the Green Android Man release all keys.
- You will be into Factory reset menu.
- Use Volume Down key to select Wipe Data / Factory Reset option.
- Use Power key to confirm the operation.
- You need to use the Volume Down key again to select "Yes delete all user data"
- Use Power key to confirm.
- After performing the hard reset, Select Reboot System Now option, And confirm it using Power key.
- Now the phone will reboots, Wait for it to be fully on and then you can start using it.
dfdvenaw make update your device via odin with this firmware:
I9300XXEMA2 / OJVEMA1 XSG United Arab Emirates(Android 4.1.2)
i hope it will work insoallah.