iMac 2009 A1312 2009 not booting - 3rd led not on

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  • sylvain_92
    New Member
    • Dec 2022
    • 2
    • France
    #1

    iMac 2009 A1312 2009 not booting - 3rd led not on

    Hi everyone,

    I am trying to repair my iMac A1312 late 2009 intel i5.

    First of all it was booting but no screen on internal lcd but working with external one,

    I tried:
    - another screen and led power board (booting no screen - same as before)
    - another mxm graphic card (not booting missing 3rd led)

    * screen and mxm gpu tested are 100% working on another A1312 iMac.

    I putted back the original mxm graphic card and what a surprise, now it's not booting anymore even with the stock parts.

    The main problem on this motherboard was a burnt inductance located around the lvds connector (L9000). I have changed it but I can't test my repair since I have tried to swap MXM GPU and putted my logicboard in bad mood.

    I took some measurement on the board and everything seems ok, graphic card is powered on and so on.

    Could it be related to PRAM ?
    Do there is any way to reset PRAM except from the usb keyboard ?

    Hope you can help me or have any idea I can dig into.

    Best regards,
    Tags: None
    • Magnamed
      New Member
      • Oct 2022
      • 2
      • Canada
      #2
      Re: iMac 2009 A1312 2009 not booting - 3rd led not on

      Hey, sorry you haven't gotten any answers. Was wondering if you'd made any progress?

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