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A1708 020-00840 liquid damage, no power

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    A1708 020-00840 liquid damage, no power

    Hi All,

    I'm working on a case for data recovery of an A1708 board 820-00840

    when I received the board it was doing absolutely nothing. I took some pictures of the corrosion and ultrasonically cleaned the board. this revealed some problem areas.

    no power via USB-C (stays at 5v 0mA, other port 5v 50mA)

    PP3V3_GH, repaired the circuit and now 3,4v present
    both CD3215 replaced, PPDCIN_3GH present at Q7030 (usb 5v 10mA)
    I did not trust the U7000 (weird impedance at Aux_det) so replaced it
    now Aux det is 1,2v and R7015, R7016 measure ok.
    now I get 5v and 40mA cycling at both USB ports, but ISL still don't want to generate PPBUS

    when I supply power to the battery terminal, (7v5) it takes 15mA and I measure this voltage also at F7000

    SMS_RESET_R_L = 3,4v at R7072
    PM_EN_P3V3_GH = 5v at R6999
    SMC_AUX_OK = 3,4v at R7071
    PP3V3_3GH_UPC = 3v3 at C3100 and C3200

    I read something about ISL92 that it should generate 12v3 at L7030, there is currently only ~200mv

    Any clues where to look for?
    www.badcaps.net
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