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820-00281 liquid on keyboard

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  • arnonabuurs
    started a topic 820-00281 liquid on keyboard

    820-00281 liquid on keyboard

    Hello, got this machine it had water liquid spil on the keyboard. The board looks superclean, only one liquid indicator is a little red on the edge of the board, looks like not much hit the board. Even around the liquid indicator that was red all looks clean. I checked voltage, it actually turns on I get 19.5v and then the Amps move up for about 15 seconds from 1.4Amps to 1.55 and then drops to 0v, 19.5v still showing. CPU also gets hot, tried to boot from external drive, light up 15 seconds and then turns off. Any ideas what could cause this? Tomorrow will start measuring all voltages but if anyone has an indication where to look, that would be appreciated.

  • arnonabuurs
    replied
    But it looks like it is running, cpu is 50 degrees and so is the gpu, and fan keeps spinning. Anyway to make sure of this?

    Leave a comment:


  • 2informaticos
    replied
    Maybe some liquid arrived to board.
    And new boards are very sensitive; dead CPU maybe...

    Leave a comment:


  • arnonabuurs
    replied
    Did some more checking it looks like i have all voltages, 1.2, 1.8, 1.0, 0.9 in S0 states

    Leave a comment:


  • arnonabuurs
    replied
    Oh i got what you are saying, the integrated graphics is not working when dedicated is turned on, which it seems it is as it gets 0.9v, correct? So this here is not the issue i guess. I also tried to boot from external HDD and although the LED burns its not flickering as it usually does when it boots. It seems the Mac is not booting up, but running.

    Leave a comment:


  • arnonabuurs
    replied
    I do have USB activity, when the mac turns on it wont switch off. You can see attached image with voltage and amps + USB mouse attached. Also I attached a Flir image, CPU and GPU seem active although L7410/20 have 0 voltage, you can see they dont heat up. I was not able to upload images so here some links:

    https://drive.google.com/open?id=1IU...3kpudE7v_X65ZP
    https://drive.google.com/open?id=1-Z...id8A4744ywoWrP

    Any hope for this board or should I call it a day?

    Leave a comment:


  • 2informaticos
    replied
    You getCPU VCORE, but no iGPU voltage.
    I know some old boards don't have iGPU voltage under low graphics charge.
    Could be similar thing here.
    And if board starts with GPU, no need to power iGPU I think.

    Check for USB activity.

    Leave a comment:


  • arnonabuurs
    replied
    Some more measurements around CPU circuit:

    PPBUS_HS_CPU = 12.59 not shorted
    PP5V_S0 to U7410/20 = 5V no short
    L7330 = 1.12v
    L7211/21/31 = 1.09
    L7410/L7420 = 0v

    Leave a comment:


  • arnonabuurs
    replied
    Yes when i connected the powercable without anything installed (so also no cooling plate) it ran upto 110 degree in 10 seconds. Now I reassembled it it keeps at 0.42 degree same as GPU, fan is spinning hapiilly, but no power to CPU. I did give it another ultrasonic before assembling, wouldnt be the first time some stuff came back to life after that....

    Leave a comment:


  • arnonabuurs
    replied
    Update, after i assembled the mac, i connected the charger one last time (battery disconnected), and fan started to spin, however this time no shutdown and it kept running. I measured voltages around CPU, actually the GPU gets 0.9 volts. CPU GPU was hot but CPU cold while fan was spinning. I get 0v on L7420, would there be a chance that the CPU powersupply failed? Or should i stop wasting my time?

    Leave a comment:


  • 2informaticos
    replied
    Does it reach 110 degrees in such short time?
    That's no good, can only be bad CPU...

    Leave a comment:


  • arnonabuurs
    replied
    I measured CPU temp with my FLircam, it shoots up to 110 Celcius, and then shuts down. Hottest I have seen a mac is 105, 110 seems not good

    Leave a comment:


  • arnonabuurs
    replied
    OK, seems I have shorts near CPU and GPU... . L8000, L7410/20 but also when i measure GPU LA640/650. I guess this is game over ?
    Last edited by arnonabuurs; 02-14-2019, 03:09 AM.

    Leave a comment:


  • arnonabuurs
    replied
    Since U7650 did output 5V for a short time i think I can skip that circuit, also no shorts here. Maybe some short in a lower powerline stops it from turning on, will keep measuring my way down and report back if i find more

    Leave a comment:


  • arnonabuurs
    replied
    Here some more measurements:

    PPBUS_G3H = 12.58
    PP3V3_G3H = 3.418
    PPDCIN_G3H_CHGR = 20.08
    SMC_BC_ACOK = 3.417
    SMC_RESET_L = 3.41
    PP3V0_G3H = 3.09
    PP3V3_S5 = 3.32
    PP5V_S5 = 5.14
    PP5V_S4 = 0v
    PP3V3_SUS = 3.3v
    PP3V3_S4 = 3.3v drops to 0 when Amps drop on meter
    PP5S_S4 on U7600 comes up after it gets enable signal, and then drops to 0 with the rest.

    SMC bypass didnt work (10 seconds holding powerbutton, keep holding 10 more while charger plugged in, correct me if thats wrong pls)

    Leave a comment:

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