How to fix iPhone 4S modem?

Question

iPhone

Recently upgraded my Apple iPhone 4S from iOS6 to iOS7. Immediately after the update, the phone refused to see the network - it sees it all the time in the search. I changed SIM, tried to update to the new iOS8, rolled back to iOS6, completely did a device restore. Everything is useless. On the Internet, I found that the problem is most likely in the Baseband software. Indeed, all the symptoms on the face - IMEI, modem version, modem mode are completely absent in the settings. The "Phone" application refuses to dial a number, 911 is missing, there are no numbers in the missed calls icon near the "Phone" icon - just a red circle, all attempts to dial a number end in nothing. As a solution - upgrade the modem, or upgrade to a new iOS. All these solutions don't work, Does that mean you have to change your phone modem? Where can you buy? How much is the question? Will the technical characteristics of the phone (IMEI, modem version, etc.) change?

Answer 1

go to the service there you will be answered immediately, completely free of charge, if you yourself are too lazy to read two links from Google.