Previous 1 4 5 6 7 8 Next 115 Replies Latest reply: Apr 4, 2015 2:20 AM by str_m Go to original post
  • taazztmc Level 1 Level 1 (0 points)

    i bought a new factory unlocked iphone 4s and faced a problem of failure in message sending and outgoing calls. the signals get droped after few minutes.. the outgoing calls get failed .. i cant send messages or make calls. sometimes it goes to as invalid sim card and some times it appears as no service. what the **** is going on . i spent that much money to face all this. help me out with this one please. what should i do..???

  • codeslayer Level 1 Level 1 (0 points)

    Update your phone with the latest frimware.

    If that doesn't help you try to talk your carrier and replace your sim card with a new one.

    If the both above solutions doesn't work for you, you may replace your SIM tray with an iPhone 4.


    Also, If possible can you give us your phone's serial number. So that we could check if it is 44th week's product. As you know some 44th week products are having issues.

  • soccerislife8 Level 1 Level 1 (0 points)

    If the above techniques didn't work, these solutions worked for me. Please let me know if they did/did not work for you. Thanks!

  • EDDERGHAM Level 1 Level 1 (0 points)

    tried all of them and nothing worked.

    plz can u inform me how to check when is my iphone 4s produced ?

    and my serial number is DNRGNDDWDTC0

    MODEL MD235B


  • BumpyDog Level 1 Level 1 (0 points)

    I was so fedup with the same problem that a lot of users have, i.e. "Searching", "No Service" and "Invalid Sim" that I took the plunge and had my phone hacked by a specialist.  So far so good.  The iphone is behaving very well and has not lost the signal at all since the hacking.  I was informed that it is advisable to have the phone replaced by Apple.  If the phone stays stable for the next week or so, then I think we have the problem solved.  South Africa has no Apple store or warrentee by Apple, so I had option but to hack it.  Once hacked, Apple wont replace it for you people who have Apple stores in your country.

  • codeslayer Level 1 Level 1 (0 points)

    Your phone is a 45th one.

    You may check by your self on


    According to my knowledge, your phone shouldn't experience radio issues after trying the methods I have provided in my previous posts. If those problems continues to happen, I suggest you to visit Apple Store and replace your phone.


    Sorry that I couldn't help you!

  • marvinfrompadova Level 1 Level 1 (0 points)

    my iphone 4s is 48 week's product, and have the same problem that lot of users have.

    i tried all the methods but nothing happens the problem is always there.

    maybe ill wait for ios 5.1..

  • mobi007 Level 1 Level 1 (0 points)

    thanks for the solutions eddergram.


    apple replaced my phone and i upgrade to 5.01 9A406 then i have invalid sim again and they replaced my phone again.


    Now how can you tell if your sim is 64 or 128?


    Also, when i insert my sim, i get on itunes: "Apple could not activate your phone, please try again later."

    Maybe because my sim had a pin on it and from middle east country - so I was forced to start from the phone.


    I disabled sim pin

    Changed carrier choice to manual - chose Bell (best roaming charges)

    Set up as new phone and syncedmy music / apps / contacts via icloud


    I will attempt to request a 128 sim from local carrier Fido or from my home country carrier STC


    Now the second phone that apple replaced to me is iOS 5.0

    Should i keep it or upgrade to 5.01 9A406?


    What features do i lose if i keep 5.0?



    My phone details:

    iPhone 4s White 64 gb

    Model MD260LL

    Modem firmware 1.0.11

    I am in Canada but using roaming chip from STC



  • mobi007 Level 1 Level 1 (0 points)

    Hey guys,


    Has anyone heard of the SHORT CIRCUIT Theory that the magnetism in the tray short circuits the sim card.


    Anyone tried the soluton of covering a part with tape seen here:



    Has it worked?



  • marvinfrompadova Level 1 Level 1 (0 points)

    i update my phone firmware to ios 5.1. the result is good, for the last 24 hrs i have not encounter any problem...

    my iphone now is working as phone. the battery life is fix.

  • Adis tsc Level 1 Level 1 (0 points)

    After update to 5.1 my iphone work great. Battery ok. Signal ok!!!!

  • HussainDawnman Level 1 Level 1 (0 points)

    It is better to keep the fw 5.0

    I am expereiencing the same problem with STC iphone 4S.

    I work in China and was told that they can't replace my iphone. حق مهضوم

    I am thinking of sending the phone to STC and have my son get a replacement (IF THEY WILL EVEN CARE).

  • mobi007 Level 1 Level 1 (0 points)

    Thanks for your reply.


    I think i found the solution:



    Apple store in Canada replaced my phone twice.

    So i have been through THREE iphone 4s's but i was still getting invalid sim.


    Apple was saying the problem not with the phone since the sim didnt work on all 3 phones

    STC said problem was not with their sim since it worked on other non apple phones.

    STC never heard of 64k or 128k sim

    (everyone blaming the other)


    They are both right. The problem is with the iOS COMMUNICATING with the micro sims as eddergram mentioned in his early post. The phone's triband technology switching from 2g to 3g and back does not link up with the sim correctly and sometimes the update to 5.01 burnt the sim so you get invalid sim.


    Just upgrade to 5.1 AND request a new sim card - your battery will be great & your sim will work fine.

    Dont bother explaining to carrier the problem, just ask for latest generation 3g sim.


    I got one from FIDO carrier in Canada and it is perfect / battery amazing with 5.1 ios


    I requested also a new STC sim from my family to send to me and i will test it when i receive.


    Hope this helps everyone.

  • darkriderz Level 1 Level 1 (0 points)

    Well since 5.1 is out my iPhone 4S is working like a charm... i made a backup and restored as new phone... Even deleted the backups on icloud...


    Now no more invalid sim errors and i even got the 3G switch... battery life is longer too... Cheerz...

  • dr.shovik Level 1 Level 1 (0 points)

    My 4S works perfectly after the 5.1 upgrade.


    - Battery life has improved significantly

    - No dropped calls for the last 2-3 days

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