So, assume that there are two Galaxy S3 phones (i9300)s. One of em has a "No Service", "Baseband Unknown" problem while the other works like a charm. Both of them are rooted and flashed with custom ROMs. (CM11 and CM12).
So, if the phone with proper /efs makes a nandroid backup of /efs and then that backup is restored in the phone having issues, then this should technically work.
Question is, will it?
dd) and definitely check out the laws in your country to make sure such activity is legal. – fattire Mar 29 '15 at 22:42