I flash my sgh-747m with stock rom "4.0.4" after flash I get unknown baseband and no imei, I think the phone needed stock modem file
can some one help me please
Not sure about SPT box....never heard of that, but it sounds like you are on either 4.3 or 4.4.2 firmware, meaning only the modem that matches the bootloader will work.
open Terminal Emulator and enter this to find your current firmware/bootloader version:
what that returns will be the modem you need to flash.