Hey, so I had some help fixing my DA120 With Testkey N3 to unlock the SD and the Image that I now have for the US SPH-DA120. You use win32 disk imager to put the image on the sd card drive once it's unlocked.
https://drive.google.com/file/d/0BzObkaTnnIcWSU82N1A2WE9uWDg/view?usp=sharing
DA120
https://drive.google.com/file/d/0BzObkaTnnIcWa1Y1UDZvYTlsWTg/view?usp=sharing
TESTKEY N3