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  1. #1
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    820-4924 Won't run on battery

    4924, liquid damage near the magsafe conn, R7005 and D7005 replaced, got power.
    Battery charges. Won't run off battery. Shutsdown immediately upon remove magsafe.
    Tried replacing ISL, Q7130, Q7155 same time. No change.
    With just battery, PPBUS measures 12.64V
    Won't power on with power button on battery only.
    Tried three total batteries, orig plus two testing batteries.

  2. #2
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    Re: 820-4924 Won't run on battery

    Is battery any good?

  3. #3
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    Re: 820-4924 Won't run on battery

    Solved. The hint is in the original problem, first line in the post. What voltage did I measure, what was missing, and what soldering mistake did I make?

  4. #4
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    Re: 820-4924 Won't run on battery

    Something with a diode My guess

  5. #5
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    Re: 820-4924 Won't run on battery

    That's what I thought! I measured voltage through the diode on battery only and surprise, no PPBUS leaving D7005 to power 3V42. So no 3v42, no boot makes sense. However, I measured the input to the diode and no PPBUS there either! It was R7005, cold joint/not attached. So PPBUS was OL across R7005. I heated it up made sure it was attached, solved.

  6. The Following 2 Users Say Thank You to BrickBreaker For This Useful Post:

    kjchatman (07-24-2019), Tellyman (07-24-2019)

 

 

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