Fifth generation of iPhone. Repair of this device is straightforward, and requires screwdrivers, prying tools, and patience. GSM/CDMA / 16, 32, or 64 GB / Black or White.

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iPhone 4S working only on 3G


I have iphone 4s and last owner probably try to fix blue coil from antenna signal but make only more damage. So when I open the phone, there was missing Blue coil (L47_RF) and also C14_RF, C12_RF, C180_RF and C183_RF. So almost everything around blue coil. I bought new coil and 33pF caps for C14 and C12, solder them on place and I get strong stable signal.

PROBLEM: making and receiving calls is possible only if I have enabled 3G. If I turn OFF 3G I still have full signal, carrier name, IMEI and everything just look fine but no way to receive or make call.

It seems like it is working only on 3G network and this is 2100MHZ band. There still missing C180_RF and C183_RF, but I think this is not the reason of issue. Now I doubt on myself if I solder properly C14 and C12 - I check under the microscope and looks fine.

Any suggestion, idea?


Answer this question I have this problem too

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I'm not sure I understand the question. When you turn off 3g, are you trying to make a phone call via WiFi? Can you possibly explain better why you need 3G off?


iPhone 4S is a 3G phone.



thank's for replay. Ok, why I need 3G off? Because making calls must working with 3G OFF. Cellular calls working only if 3G is ON. If I turn 3G OFF, so phone probably switch to another frequency (2G probably) from this moment I'm unable to make calls. If I turn ON 3G back again I'm able to make calls again.

Yesterday I put back all missing components and it is no difference. Still same issue. I sit down and play with calls from another phone and from iphone. Then suddenly with 3G OFF I receive SMS on defected iphone about missing calls. Immedietly I try to call from iphone (3G OFF) and I was able to make and receive couple of calls and after some minutes again nothing. All the time there was full signal of carrier.

Brad, I agree Iphone 4S is 3G phone, but making calls also must work if I turn OFF 3G.



Have you contacted your Carrier in regards to this issue?


No, not jet. I'm 90% sure this is iphone problem, not carrier. My girlfriend has also iphone 4S and work without problems with 3G OFF. Difference is only in iOS versions (my is up to date with iOS 8.)

Now about one day I use it with 3G OFF. Of course most of time number is not avalible (full or one missing signal indicator). And then suddenly it is avalible. In one moment I get feeling like if I hold phone in my hand then is not avalible. I try to cover aluminium bezel with tape, but there is no difference - Sometimes number is avalible, sometimes replay autoresponder. I start to suspect now cellular antenna at the bottom of phone. Because when I start to repair this poor damaged phone I found shortcut on this antenna, then I found failure where cable is soldered on antenna ribbon it was soldered together with shield. But this was fixed (or at least I think so).


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1 Answer

Take your phone to the nearest Apple Store or send it to both places can fix this issue. The issue is both your carrier and the person who owned it before you. Sorry to disappoint but it's not going to be cheap... :(

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