Originally Posted by ironside2011
Hi everyone, I recently switched from a galaxy nexus to the gs3. And yes I've read through all the threads and such with similar question. However, they all seem to have the topic issue from flashing a bad ROM. My gs3 though is totally stock running 4.3 and has already had the Sim card switched out. Is there a solution to fix the mobile network type unknown
Try powering down the phone, removing the sim card, and blowing into the card slot like an old Nintendo game cartridge. Make sure the contacts on the sim card are clean, then reinsert and power back up
May sound crazy but it's worked for me in the past.
Also make sure your GS3 isn't in GSM mode under settings > wireless and networks > more settings > mobile networks > network mode