Procedure:
1. Phone must be powered on.
2. Type *#7284# and choose phone usb.
3. Type *#197328640#, select: Common - Diag Config - USB diag.
4. Reboot phone.
5. Connect USB cable, install drivers.
6. Select diagnostic port in port settings.
7. Press "Read Info" button.
8. Press "Unlock" button.
1. Phone must be powered on.
2. Type *#7284# and choose phone usb.
3. Type *#197328640#, select: Common - Diag Config - USB diag.
4. Reboot phone.
5. Connect USB cable, install drivers.
6. Select diagnostic port in port settings.
7. Press "Read Info" button.
8. Press "Unlock" button.
..::Samsung T679 T-Mobile lock Successfully Unlocked::..