Hi guys, after so many attempts to regain my iphone 6 signal are failed...this is what i try,eject your sim tray,open your iphone and slightly lift the 6 copper pin on the sim connector up using small needle. The objective is to tighten the connection between copper plat of the sim to the copper pin of the iphone and praise the Lord miracle do happen. After inserting my sim and powering up...there they are,5 dot bars of signal appears on my Iphone 6. Hope it will work on your problems too...never give up!