Results 1 to 7 of 7
  1.    #1  
    To All,

    I have recently been given a TREO 600 from a good friend. It is totally cleared. It was part of the old AT&T, and it has no SIM card. I am part of the new Cingular that swithed to AT&T that is now the new AT&T (how confusing). I just want to know what do I have to do to get my TREO operational. Do I just buy another SIM card, or do I have to cancel my current service with cingular and switch or what? I just want my phone to work, but I don't want to give up my current plan, or pay any more if I can help it. (hahaha) My wife and I both share this cingular plan, but only I have the TREO. I would like to use my TREO with my current plan. That's basically it in a nut shell. All help will be greatly apreciated.


  2. puyi's Avatar
    296 Posts
    Global Posts
    297 Global Posts
    Try to install your Cingular SIM, most likely it's locked. If your friend still has a Cingular account ask your friend to call Customer Service and ask them for an unlock code. If that doesn't work, there are numerous 3rd party Unlocking Services.

    Be aware that the AT&T 600 may not be optimized for the Cingular, (now new AT&T network).
  3. #3  
    I have a Treo 600 that was purchased 3 years ago and locked to the AT&T network. When Cingular bought AT&T and said we had to upgrade our SIM cards to Cingular ones, they said they couldn't unlock my phone for me because they didn't get the unlock codes from AT&T after the merger. I wasn't about to give up my 600 so I tracked down how I could unlock it, for free!

    The friendly folks over at MyTreo.Net (MTDN for short) have a firmware update and instructions that will allow you to unlock your 600 and then use a Cingular (or any other GSM) SIM card in it. Just search their forum for "Treo 600 unlock" and you will find a thread where you request the updater file and then someone will PM (private message) it to you. You'll need to register in the forum first, just like you did here at TC.

    It was really easy and worked the first time. No problems since, either.

    Good luck!
  4. #4  
    Actually, you can do a software unlock on the GSM 600 series for free if it is currently locked. I did this back when I had a 600. Checkout this thread - LINK

    edit: eTreo beat me to it
    Treo 600 > Treo 650 > Treo 700p > Treo 700wx -> Mogul -> Touch Pro
    You may like to flash, but your phone shouldn't. LED Killer
  5.    #5  
    Thanks for the reply guys, I ahve already registered, and posted a message. hopefully I will get a reply soon.

    thanks again.

  6.    #6  
    Hey wassup,

    I have been trying to to this, but in the instructions it tells me to copy all of the files from this zip file to the install tool. i have no clue as to what they are talking about. Need help!!! please.........
  7. #7  
    1. u need palm desktop installed on u'r pc. (u may need to go to, find link, give HEX# from the back of the phone and download).
    2. On the left side of palm desk is the 'install tool'. Click to open. drag unzipped .prc files to install. and click 'done'.
    3. Hotsync your phone. oh, you should not install one your first Hotsync.

Posting Permissions