MacBook Pro mid-2009 supply (magsafe related.

Discussion in 'MacBook Pro' started by ntrn, Nov 25, 2015.

  1. ntrn macrumors newbie

    Joined:
    Nov 25, 2015
    #1
    I have a mid-2009 MacBook Pro, Core2Duo 2.26GHz, nVidia 8400M vídeo, 8 GB RAM, fusion drive (120GB SSD 750GB HDD). All working fairly normally, considering its age.
    Recently I bought a new 60W power supply. Though it was apparently working OK for the first few days, earlier today the power supply would not charge anymore. No LED signal, no LED lit up and no charging indication on the menu bar.
    Since the battery is now over, I tried to measure the voltages directly on the board. I wired up my MagSafe adapter and connected the VCC lines to de VCC lines and the GND lines to the GND lines of the DC in board, thus bypassing the MagSafe connector. When I measure the voltage entering the the DC In board, I get 16.26V as expected.

    However, I can't turn on the machine, it behaves like there's no battery charge at all. No white screen on boot, no startup chimex nothing. It simply doesn't turn on. Tried doing it via the power button and the power pads, but nothing works.

    Do you guys have any suggestions about what can be happening here? I can't figure out if this is a supply problem or if it is some problem with the MacBook itself. I also can't take it to a Genius Bar because there is not a single genus bar service (or any Apple Store) here.
     

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  2. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #2
    Did you verify that there is voltage on the logic board?
    Your pictures show you have connected the power adapter directly to the magsafe board, and not really bypassing the magsafe board at all. If a fuse is blown on the magsafe board, you would still measure voltage on the magsafe board, but no voltage would get to where it is supposed to go - the logic board. Check instead for voltage beyond the connector that runs from the magsafe board to the logic board.

    If you don't have voltage on the logic board, but you do have good voltage on the magsafe board - try replacing the magsafe board next (that's the part that you might call a DC-in board - Apple calls it a magsafe board) That's a lot cheaper (and simpler to replace :D )
    An Apple store will quickly tell you that the mid-2009 MBPro is now considered vintage - soon to be obsolete - no support directly from Apple.
     
  3. ntrn, Nov 26, 2015
    Last edited: Nov 26, 2015

    ntrn thread starter macrumors newbie

    Joined:
    Nov 25, 2015
    #3
    Thanks, DeltaMac.
    You're right, I did not test for voltages beyond the connector. Where should I measure some known voltage on the board?

    Also, before trying to connect the power adapter to the DC-in board, I had connected the supply right into the main board, thus effectively bypassing the MagSafe connector. The voltage measured across VCC-GND was about a little less than 4 V. I also couldn't turn the computer on with these wirings.

    Thanks,
     
  4. ntrn thread starter macrumors newbie

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    Nov 25, 2015
  5. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #5
    I think you would also need to try to power on through the power pads, which are on the logic board. That would bypass the keyboard power button, just in case that is part of your problem. If you have a service manual for your MBPro, it's easy to find the power pads. Maybe you have already tried that.
    If so - and you still have low voltage when checking on the logic board, then most likely the problem is the logic board power circuit, maybe a blown fuse. You would really need to know what you are doing to fix a blown fuse. It's something I have never tried, although you might read about some success with that. Modifying the logic board is not for the faint-of-heart.
     
  6. ntrn thread starter macrumors newbie

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    Nov 25, 2015
    #6
    Hi, DeltaMac. I indeed tried to power up the machine shorting the power pads before, but with no luck. I'll try connecting the supply again and measuring voltages on the board. It sure looks like it's a blown fuse. I'll post back if I find something. Thank you.
     
  7. ntrn thread starter macrumors newbie

    Joined:
    Nov 25, 2015
    #7
    I connected the power adapter right into the MagSafe pins (without bypassing the DC In circuit, just like it would be if I normally plugged in the MagSafe cable) and I measure the correct 16.26 supply voltage.
    I have measured the voltage between the power pads, which read 3.4V as it should be. However, I can't turn it on. I have the schematics for the board, but I can't seem to find where would the problem be, since the board is apparently powered up correctly.
     
  8. DeltaMac macrumors 604

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #8
    I think that the low voltage at the power pads doesn't tell you much.
    Try tracking the voltage that gets to the battery. You may be able to look at that voltage at the battery connector on the logic board. You would have the battery disconnected to do that, of course. (you may also get voltage to the power pads if the battery is connected, so that's another reason to leave the battery out of the circuit.)
     
  9. ntrn thread starter macrumors newbie

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    Nov 25, 2015
    #9
    Plugged in with the battery disconnected, I'm getting no voltage on the battery connector.
     

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