Mobo initial power up circuit

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  • Calchaqui
    Senior Member
    • Oct 2005
    • 112
    #1

    Mobo initial power up circuit

    Three Asus mobos with co-related problems. When plugged to AC, mobo tries to power up by itself for 4 sec speening fans and turn off, when press switch, power up OK and boot, without cmos battery I need to power it up 2 times to boot (seems it needs to fully charge some caps). I checked the cmos-battery-southbridge lines for shorted diode and seems ok.
    Electrolitics all Rubycon good caps, am i looking here for:
    1)some big mosfet kinda shorted,
    2)small smd cap or resistor shorted
    3)PWM IC problem,
    4) Electrolitic caps problem ?
    I LOVE WWW.BADCAPS.NET
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