AU KDDI sim card with AT&T iphone 4s?

Discussion in 'iPhone' started by sailorssiren, Aug 11, 2014.

  1. sailorssiren macrumors newbie

    Joined:
    Jun 29, 2014
    #1
    AT&T unlocked my iphone4s for me and said it would work with any over seas gsm carrier. well im living in japan and i have AU. they are both CDMA and GSM. i already had a sim card. when i put it in the phone it just continually says searching, eventually it might say no service, it also has a pop up that says it needs to be restored with itunes. i have done that. still nothing. am i doing something wrong??

    i have followed many steps and i have gotten no where. i also heard about an APN configuration thing? but it said dont attempt unless instructed to and since i am not exactly tech savvy i didnt want to risk making anything worse.

    someones please help :((
     
  2. EDH667 macrumors 6502a

    EDH667

    Joined:
    Nov 25, 2009
    Location:
    Northern California
    #2
    An unlocked iPhone 4s will only work with any compatible worldwide GSM. I'm guessing that provider doesn't use the same GSM Band that is on the iPhone 4s. The 4s uses the following bands:
    GSM: 850, 900, 1800, 1900 MHz
    UMTS: 850, 900, 1900, 2100 MHz
    You may want to check with that provider to see if they are compatible or find one that is.
     
  3. sailorssiren thread starter macrumors newbie

    Joined:
    Jun 29, 2014
    #3
    but if the phone company im with has an iphone 4s wouldnt they run the same?
     
  4. EDH667 macrumors 6502a

    EDH667

    Joined:
    Nov 25, 2009
    Location:
    Northern California
    #4
    I would check with the provider, maybe their iPhone 4s is running on CDMA.
     
  5. sailorssiren thread starter macrumors newbie

    Joined:
    Jun 29, 2014
    #5
    if it has a sim card can it still be CDMA? i emailed them since they never seem to answer the english support line
     
  6. EDH667 macrumors 6502a

    EDH667

    Joined:
    Nov 25, 2009
    Location:
    Northern California
    #6
    Yes, an example in the US is Sprint and Verizon. They are CDMA based but use SIM's for their LTE networks. Some phone carriers use CDMA but have unlocked GSM SIM card slots for use overseas.
     
  7. Imhzw macrumors newbie

    Imhzw

    Joined:
    Aug 5, 2014
    #7
    You could go to Apple.com to see the model's network supports.

    But AU seems a CDMA carrier.

    For a LOCKED phone and unlocked later, it is hard to support another CDMA carrier. Some people call this need to flash iPhone in order to import new carrier's setting.

    For me, Sprint 5c. When I find unlocking only unlocks GSM, I gave up.

    Maybe you can see Softbank's network.
     
  8. sailorssiren thread starter macrumors newbie

    Joined:
    Jun 29, 2014
    #8
    i already have a service with AU so i cant just leave their service i was just trying to make my old iphone 4s work with the network since my dad just sent it to me from the states. but i have been told that AU is both CDMA and GSM. not just one or the other. i am still waiting an email response so i will post the findings when they get back to me.

    when i go on the apple website it only shows me the 4 US carriers so that wont help me at all. iphone is supposed to be a "World phone"
     
  9. Acronyc macrumors 6502a

    Joined:
    Jan 24, 2011
    #9
    I've been with AU ever since I got my 4s (still going strong) in January 2012. AU is a CDMA carrier here and I'm not sure if an unlocked 4s from outside Japan will work on their network. My AU 4s can roam on GSM networks in other countries but I don't think it works the other way around. Hope I'm wrong though and you can get it working!
     
  10. sailorssiren thread starter macrumors newbie

    Joined:
    Jun 29, 2014
    #10

    sadly you are correct, they are CDMA for their iphones but they are gsm with other phones such as the galaxy (which is what i currently have) here is the email i received from them :

    "Thank you very much for your inquiry.  I am Fujihira.
    You iPhone is not a SIM free iPhone which was sold by AT&T.
    Thus, regardless of whether the frequencies are compatible or not, we cannot
    accept the phone.

    If you buy the SIM free iPhone from Apple in Japan, we can make a contract with
    you, unless you have an outstanding balance on your account.

    In addtion, au IC card(SIM) is provided based on the assumption that it is used
    with au phones.Therefore, if you insert it into the unlocked SIM Free devices,
    we au do not guarantee or support operation when au IC card is used with other
    company's unlocked phone not au phone.

    I am very sorry that I cannot be of more assistance at this time."


    hopefully this forum post can at least assist someone else before they make the same mistake i did :( i was very mislead by someone else saying they used their AT&T phone.
     
  11. Acronyc macrumors 6502a

    Joined:
    Jan 24, 2011
    #11
    That's too bad to hear and sorry you couldn't get it working. One option if you want to use an iPhone is to sell your phone on Craig's List or Yahoo Auctions (you'll get more for it on Yahoo) and pick up a used 4s here.

    Or as the email mentioned you could get an unlocked one here in Japan from Apple, which will work on the three big carriers and in other countries. Apple just recently started selling SIM free iPhones in Japan and I'll be taking that route for sure when I upgrade next time.
     
  12. Imhzw macrumors newbie

    Imhzw

    Joined:
    Aug 5, 2014
    #12
    I'm a CDMA user in China Telecom. If you want to use its cdma service, you could buy its locked phones or Verizon iPhone which the activation policy is 2023 or some USA Cellular phones. For a Sprint LOCKED phone and unlocked then officailly, it seems not support the cdma, which mean unlocking only unlock GSM. The lock principle is different between cdma and gsm.

    But there are always some cases. Some Sprint iPhone 5 unlocked by sending email could use cdma. The activation policy 10 unlock is GSM unlock, but when your phone is iOS6 this activation policy supports CDMA. Now I'm really confused that is Apple and carrier's limits or the phone itself's technical problem that disable its cdma network in other cdma carriers.
     

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