Try #*7337#
If it fails try
1.) Put a non accecpted SIM card in the phone.
2.) If you see Wrong Card type #9998*3323#
3.) Press Exit and choose number 7. Phone will reboot.
4.) That SIM should now work
5.) Type *0141# and then hit Call
6.) Power off the phone and insert another SIM card
7.) If ask you for a code, it's 00000000