Power down and master/slave socket

Discussion in 'Asus' started by Karsten Priegnitz, Jan 31, 2004.

  1. Hi,

    I've got a master/slave socket (the ones that switch all the devices off
    when the master device is turned off) to which I connected my PC as master
    and my monitor and speakers as slaves. When I shut down the PC this doesn't
    work until I turn off the ATX power supply unit with its little switch on
    the back of the PC. Then the slave devices turn off and they even stay
    turned off when I turn on the ATX unit again. When I boot up the PC the
    slaves turn on again.

    I have an Asus P4B-533M motherboard. Is there a possibility to make it turn
    off completely when shutting down the PC?

    Karsten Priegnitz, Jan 31, 2004
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  2. Karsten Priegnitz

    Muttley Guest


    An ATX power supply provides standby power to the motherboard at all times
    after shutdown.
    This is so the motherboard can detect when you press the power button on the
    front of the PC, or the modem ringing or a LAN wake up signal and then turn
    itself on.
    This can only be stopped as you have noticed by turning off the master
    switch on the power supply, if it has one (some do not).

    John S.
    Muttley, Feb 1, 2004
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  3. Karsten Priegnitz

    Paul Guest

    That is because the power supply is still running and producing +5VSB,
    after Windows shuts down. This means the power supply is still consuming
    a few watts. If the master/slave device had a sensitivity setting,
    maybe making it less sensitive would work.

    What I like to do with today's power leaking devices, is put them
    all on a power strip (six outlets plus switch). Then, at the end of
    a session, I just flip the switch on the strip and all the "wall warts"
    and standby power sources are all switched off. Even my LCD monitor
    continues to draw current after it is shut off, so a power strip is
    a cheap solution to the problem.

    Depending on how your external speakers are designed, you might get
    a big "whomp" from the speakers when they are switched off at the
    wall. My cheap speakers shut down more quietly if switched off by
    the switch on the front of them.

    Paul, Feb 1, 2004
  4. A friend of mine has bought a new PC and uses the same master/slave socket
    bar as I do. It works with his mainboard. And as I wrote: when I turn of
    the master switch on the ATX power supply and turn it back on the bar stays
    "switched off". It seems to be possible to turn an modern PC on without
    having power on the mainboard...

    strange strange strange ...
    Karsten Priegnitz, Feb 1, 2004
  5. Karsten Priegnitz

    Muttley Guest

    You can adust a setting in the BIOS to make the PC bootup as soon as AC
    power is applied to the unit.
    "AC Power Loss Restart" in Power Options.

    The power bar will have a detection threshold that determines how much
    current flow is required to turn the slave sockets on, and another threshold
    that determines how low the current flow must be to turn the slave sockets

    In your case, the power supply is drawing too much power after shutdown
    (above the turn-off threshold) to allow the slaves to turn off.
    The slaves only turn off after you turn off the main switch on the power
    supply, which reduces the current flow to zero.
    Also, when you initially turn on the main switch at the power supply, it is
    not drawing enough power (below the turn-on threshold) to trigger turn-on of
    the slave sockets. The current only goes above the threshold when you press
    the power button to boot the PC.

    Either his power bar has a higher threshold for slave turn-off or his PC
    draws less power in standby than yours and therefore allows the slaves to
    turn off at shutdown. Perhaps your power bar could be faulty too.

    John S.
    Muttley, Feb 1, 2004
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