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  1. #1
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    2019 A1989 820-00850 Liquid damage some signs of life

    A1989 820-00850 13 Touchbar


    Will not boot however I can plug in the usb-c charger and it will make the connection chime that the mac has been plugged to power source. Not the power on chime , but a connection chime that the cable has made contact.

    There is no backlight OR image , blank. The keyboard caps light also does not come on .

    I found liquid damage at the eDP connector (lcd display connector ) it was preety bad but I managed to clean this up, still no BL or image. I've read where these macs can become useless because there is 52v on a data line to the cpu as the backlight?


    Backlight fuse is showing 12v however Q8400 pin 3,4 show 12v when I test pins 1,2,5,6. I get a slow voltage drop till it gets to 0
    Last edited by John626; 03-17-2020 at 01:43 PM.

  2. #2
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    Re: 2019 A1989 820-00850 Liquid damage some signs of life

    Think this cpu is shot I have no cpu vcore i'll give it a shot but these boards at with the display connector Liquid damaged usually don't end up good.

  3. #3
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    Re: 2019 A1989 820-00850 Liquid damage some signs of life

    Do you have a USB-C meter? this is very important to have so you know how much power going into the board and how many Amp taking the board with the battery unplug.

  4. #4
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    Re: 2019 A1989 820-00850 Liquid damage some signs of life

    No I did order one now ....the cpu coils have been removed and there is def a short ...this cpu is no good. Have to wait till I can get a CPU compatible with this board.

  5. #5
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    Re: 2019 A1989 820-00850 Liquid damage some signs of life

    Quote Originally Posted by John626 [Only Registered and Activated Users Can See Links. Click Here To Register...]
    No I did order one now ....the cpu coils have been removed and there is def a short ...this cpu is no good. Have to wait till I can get a CPU compatible with this board.
    FYI the CPU is very low resistance. Try inject 1volt see if the CPU getting HOT.

  6. #6
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    Re: 2019 A1989 820-00850 Liquid damage some signs of life

    Quote Originally Posted by John626 [Only Registered and Activated Users Can See Links. Click Here To Register...]
    A1989 820-00850 13 Touchbar


    Will not boot however I can plug in the usb-c charger and it will make the connection chime that the mac has been plugged to power source. Not the power on chime , but a connection chime that the cable has made contact.

    There is no backlight OR image , blank. The keyboard caps light also does not come on .

    I found liquid damage at the eDP connector (lcd display connector ) it was preety bad but I managed to clean this up, still no BL or image. I've read where these macs can become useless because there is 52v on a data line to the cpu as the backlight?


    Backlight fuse is showing 12v however Q8400 pin 3,4 show 12v when I test pins 1,2,5,6. I get a slow voltage drop till it gets to 0
    I have exactly the same symptoms with the same board ....beer spill. I replaced the burnt eDP connector LCD side . Tested screen using 2017 logic board ...screen now works. Still nothing on original board except sound of charger connection / trackpad click.
    Schematic available ?

 

 

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