sgs5 service menu
although I don't think theres a way to unlock it just yet I been digging through the service menu and can't find network lock control. also once I think i'm getting close the sim card tray stops working for sprint sim cards. had to take one back xD but then found out that RTN the phone fixes it. NV rebuild doesn't have a golden back up and there is no way to make a back up or restore a back up from the phone service menu.