One day after downloading an application my Samsung A12 turned off and never went on. After being fixed by technician,sim cards don't ever work in it it just portrays network not registered
Contact Samsung by opening the Members app, go to Support on the bottom right corner and scroll untill you see Error Report. Click on it and follow the steps
Another question: Which technician fixed your phone? It sounds like it went into bootloop, and they reloaded the software. If the technician does not know what he is doing, he might not have downloaded the part that configures the bands in which configures the signal to our towers!
