Welcome to MacTalk Australia

the largest Australian community for Apple discussions and topics

Join the discussions, Register Now!
Results 1 to 13 of 13
  1. #1

    Join Date
    Jul 2005
    Location
    Brisbane, Australia
    Posts
    651

    Default 3G to 2G - changing SIM cards

    It's exciting stuff, my iPhone has been put in the mail! Expecting it to be delivered next week

    My only worry is that I currently have an Optus 3G sim card. I have an old 2G sim that is also Optus. How do I go about moving my service from 3G to 2G? I don't even know if it's possible, haha.

    Does anyone have experience with this?

    Thanks,
    Mitch
     My Mac Stuff: 15" MacBook Pro 2.2 i7 8GB RAM and iPhone 5 32GB
     Successful Trading: anaami, areal, Huy, mattcooper, TheKeddi, KunfuCamel, gumby08

  2. #2

    Join Date
    Dec 2007
    Posts
    373

    Default

    I'm with Telstra just stuck my 3g card in and all worked fine.
    IMAC 2.4 : iPhone 3g
    MacBook Air 1.8 80g : MacBook Pro : Mac Pro 2.8 Nikon D90 - D300s 18-105 VR / 70-300 VR / 50mm / Sigma 24-70 F2.8

  3. #3

    Join Date
    Aug 2007
    Location
    Sydney
    Posts
    5,185

    Default

    You'll probably just have to make a new 2G account with Optus and transfer the number from the 3G account.

  4. #4

    Join Date
    Mar 2005
    Location
    elssewhere
    Posts
    2,736

    Default

    just use the 3G sim, it will only work as a 2G sim in the iPhone but it will still work.

  5. #5

    Join Date
    Jul 2005
    Location
    Brisbane, Australia
    Posts
    651

    Default

    Ah, so the sims are backwards compatible! That was smart thinking.
     My Mac Stuff: 15" MacBook Pro 2.2 i7 8GB RAM and iPhone 5 32GB
     Successful Trading: anaami, areal, Huy, mattcooper, TheKeddi, KunfuCamel, gumby08

  6. #6
    Comet's Avatar Comet is offline Addicted to anything made by Apple

    Join Date
    Jan 2004
    Location
    Melbourne
    Posts
    1,893

    Default

    USIMs backward compatible. Anyways, operators should be preventing users from downgrading from a 3G to a 2G. The commercial offers on a 3G plan don't necessarily equate to something in the 2G plan.

    If you're with 3, you can't stick their SIM into a 2G phone unless you signed up when they first came out.
    Macbook Pro 2.4Ghz Unibody goodness
    20 Inch Cinema Display
    8Gb 3G iPhone, 3rd gen iPod Nano 4Gb, 3rd gen U2 ipod 20Gb

  7. #7

    Join Date
    Jan 2005
    Location
    Penrith, NSW
    Posts
    1,576

    Default

    3G and 2G have different SIM cards? Are you sure?

    I had an old 2G phone, and when i got my 3G phone and also wanted to keep the same number i simply used the same old SIM card from the 2G phone, and it works perfectly.
    My gut is telling me no... but my gut is also very hungry...

  8. #8

    Join Date
    Aug 2007
    Location
    Sydney
    Posts
    5,185

    Default

    Sorry my bad, I'm the wrong one, I was thinking of 3, but thats not because the SIMs are different it's because of 3s Network.

  9. #9
    asphotos's Avatar asphotos is offline more elephants

    Join Date
    Jul 2004
    Location
    Mascot, Sydney
    Posts
    998

    Default

    an operator can (and does) someitmes turn access control and other function on, and these are only found in usims,.

    3 (huth) has access control based on usim turned on.

    but, not all networks need a usim to access 3g,

    any optus sim will work in (most) phones on the market and as such, sim form 4-5 years ago will come up on 3g in a new nokia n95. (or iphone 2.0)

    some of the really really old sims were 5v and 3.3v and the newer handsets are not compatible with these old sims (mid 90's)..

    the above being said, some of the partner networks (when roaming) need a Usim and your 3g device wont work on 3g in the partner country.
    Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese
    Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese
    Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese Cheese

  10. #10
    Exocet's Avatar Exocet is offline We're gonna need to move you down into storage B.

    Join Date
    Aug 2004
    Location
    Sydney
    Posts
    5,333

    Default

    Quote Originally Posted by tommelbourne View Post
    3G and 2G have different SIM cards? Are you sure?

    I had an old 2G phone, and when i got my 3G phone and also wanted to keep the same number i simply used the same old SIM card from the 2G phone, and it works perfectly.
    Depending on how long ago you were given the SIM Card by your carrier, it may already be a 3G SIM. However, if you're using a 2G SIM in a 3G phone - you will be limited to 2G-only features. There are three pieces to the 3G puzzle...a 3G SIM, a 3G phone and 3G coverage. If one of those pieces are missing it will fall back to 2G.

  11. #11

    Join Date
    Jan 2005
    Location
    Penrith, NSW
    Posts
    1,576

    Default

    Quote Originally Posted by Exocet View Post
    Depending on how long ago you were given the SIM Card by your carrier, it may already be a 3G SIM. However, if you're using a 2G SIM in a 3G phone - you will be limited to 2G-only features. There are three pieces to the 3G puzzle...a 3G SIM, a 3G phone and 3G coverage. If one of those pieces are missing it will fall back to 2G.
    Hmmm. It says 3G in the top-corner of my phone, just under the signal strength. I got the SIM about 5 or 6 years ago - would that make it a 3G SIM? I did notice that it looked slightly different underneath compared to the new SIM that came with the phone.
    My gut is telling me no... but my gut is also very hungry...

  12. #12

    Join Date
    Jan 2004
    Location
    Dee Why, Sydney
    Posts
    3,371

    Default

    How many pins does it have? USIMs have 8 pins, 2G SIMs have 6.
    Good. Fast. Cheap. Pick two...

  13. #13

    Join Date
    Jan 2005
    Location
    Penrith, NSW
    Posts
    1,576

    Default

    Quote Originally Posted by LCGuy View Post
    How many pins does it have? USIMs have 8 pins, 2G SIMs have 6.
    The SIM itself has 8 pins. However, the phone only has 6 pins, so only 6 of the contacts on the SIM are being used.
    My gut is telling me no... but my gut is also very hungry...

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •