Results 1 to 5 of 5

Your favorite Apple, iPhone, iPad, iOS, Jailbreak, and Cydia site.

Thread: iPhone 3gs replacement back does not detect Sim inserted

  1. #1
    Default iPhone 3gs replacement back does not detect Sim inserted
    So I bought a pre built back with the battery, dock, wifi antenna etc. Ready to put a logic board and screen and go. So I put in a known good 3GS Jailbreak to 5.01 and unlocked logic board, put the screen on, power it up and everything worked fine. When I inserted the Sim the iPhone could not detect that it was inserted. Put the board in any other back and it works fine. Same Sim; Same tray. My question is how is the Sim detected? I thought it was all on the logic board.

    Any ideas?

    Last edited by mateo1961; 2012-05-08 at 11:20 PM.

  2. #2
    OK after 20 Sim trays I was able to find two that would let the Sim be detected.

    I was just wondering how the Sim is detected. Is it read through the six connectors or is there another mechanism that detects a Sim tray is inserted then the card is read?
    I need to better understand the mechanism so that I can fix the logic board so it would detect the Sim every time with any tray.


  3. #3
    Try this. Make SIM Tray longer. Take a SIM Tray that does not work. Add a bit of tape, plastic, paper whatever you like and add it to the very end of the SIM Tray, to make it about a half mm longer.

    Why this would work. You new back is out of specification, not perfect size. Maybe a slightly longer SIM Tray will now press the copper wire switch deep in the SIM Bay to get the iPhone to read the SIM Card.

  4. The Following User Says Thank You to 805 93003 For This Useful Post:

    mateo1961 (2012-05-10)

  5. #4
    Thank you for the response.

    I had always thought that the wire was a spring to pop the tray out. LOL.
    So that wire on the bottom when no tray is in makes a short with the other wire. When a tray that does not work is inserted it barely touches the wire and does not open the wire. When a tray that works is inserted it breaks that connection.

    That was the information I was looking for. Thanks.

  6. #5
    To close this thread, I was able to loosen the screws on the logic board and gently push the board forward enough that now any tray can be read.


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