So my dad got back from China yesterday, and he got me a clone s6 Sm-g920f, I knew it was a clone but he picked the best one he could. He knew what he was looking for. It's a good copy, physically identical. And the software looks good. The only problem with it is, when I put in a sim and try to make a call is says "mobile network not available". I've tried everything on the Internet such as selecting the network but it won't register. I have dialed *#*#4636#*#* and turned radio off and changed it to GSM auto but no luck. I was thinking that if the hardware is there, and it seems to be, if I could flash a copy of a legitimate copy of Android 5.0 for the s6. I was hoping this would remove any of the Chinese software that was on there. Could anyone please assist me on this? I signed up to this forum just to ask this. So sorry if this is the wrong section.