MACBOOK: Basic safety question before injecting voltage

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  • JM1010
    Member
    • Sep 2021
    • 16
    • Canada
    #1

    MACBOOK: Basic safety question before injecting voltage

    A1707 PPBUS has a partial short to ground @ 50 ohms.
    VCORE to ground is 4 ohms.
    Between PPBUS and VCORE I get 50 ohms as well.
    Is it safe to inject 1-2 volt into PPBUS?

    I remember piernov on Logiwiki stating that if PPBUS ohms to ground is LOWER than VCORE ohms to ground it is probably safe to inject small voltage into PPBUS. If it's the same resistance to ground it is not. But what about when PPBUS resistance to ground equals resistance between PPBUS and VCORE eg 50 ohms AND VCORE resistance to ground is lower eg 4 ohms? Is it safe to inject voltage into PPBUS
    Last edited by JM1010; 12-20-2021, 12:22 PM.
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