Microsoft Mouse stays lit when computer is off. (A8N-SLI Premium)

Discussion in 'Asus' started by HST, Jun 29, 2005.

  1. HST

    HST Guest

    I already know now that the A8N-SLI Premium has a power LED that stays
    lit when the computer is off and it is normal but when I shut down the
    computer the Microsoft Intelli-mouse light stays lit, what gives and
    how do I rectify it?

    HST

    geezzz, one problem after the other :eek:)
     
    HST, Jun 29, 2005
    #1
    1. Advertising

  2. HST

    jroc Guest

    On Wed, 29 Jun 2005 11:42:40 -0400, HST <> managed to one finger
    type the following:

    >I already know now that the A8N-SLI Premium has a power LED that stays
    >lit when the computer is off and it is normal but when I shut down the
    >computer the Microsoft Intelli-mouse light stays lit, what gives and
    >how do I rectify it?
    >
    >HST
    >
    >geezzz, one problem after the other :eek:)


    I have the Optical Wireless Mouse 2.0...and its connected via USB2....the
    Transmitter turns off..when I power off...but of course the mouse has separate
    batteries..but goes into the 'power saving mode' (very dim red light)...I'm on a
    ASUS A7V333.

    "De Oppresso Liber"
    From Oppression Liberate

    jroc® 7th Special Forces Ft.Bragg N.C 18/Bravo
    ****only thing easy in life is failure****
    *******so get tough*******
     
    jroc, Jun 29, 2005
    #2
    1. Advertising

  3. HST

    R. B. Guest

    "HST" <> wrote in message
    news:...
    >I already know now that the A8N-SLI Premium has a power LED that stays
    > lit when the computer is off and it is normal but when I shut down the
    > computer the Microsoft Intelli-mouse light stays lit, what gives and
    > how do I rectify it?
    >
    > HST
    >
    > geezzz, one problem after the other :eek:)


    Go into the bios to power, then to APM Configuration and set the Restore on
    AC power loss to [Enabled]. Both of your problems will go away. no more
    green light on after you shut down and the mouse light will go out. You will
    also save power. Set your surge protector so that all of your components
    will be on when you turn on the master switch. You will also save the wear
    and tear on all the switches except the master on the surge protector.Use
    the master switch to turn on and off your computer. I run ever computer that
    I build like this. No problems. Hope this helps.
    R. B.
     
    R. B., Jun 29, 2005
    #3
  4. HST

    Mercury Guest

    This setting is for use when you have a UPS. It means that if the system is
    shutdown by a UPS (Power Loss) restore the system state to the prior state.
    IE if the system was running, restart it, if the system was powered off ,
    leave it off.

    If you do not have a UPS, it is best to have it disabled as otherwise if you
    have a rapid series of power failures you will blow up your system - just
    like repeatedly turning the power for a light on and off will blow it.

    The OP's mouse problem actually sounds like normal behaviour - the mouse
    will go idle and turn off the light, but if it is moved it will turn on. One
    of the Wake on xxxx settings may disable it.



    "R. B." <> wrote in message
    news:eek:Dzwe.7345$dz6.6739@trnddc02...
    >
    > "HST" <> wrote in message
    > news:...
    >>I already know now that the A8N-SLI Premium has a power LED that stays
    >> lit when the computer is off and it is normal but when I shut down the
    >> computer the Microsoft Intelli-mouse light stays lit, what gives and
    >> how do I rectify it?
    >>
    >> HST
    >>
    >> geezzz, one problem after the other :eek:)

    >
    > Go into the bios to power, then to APM Configuration and set the Restore
    > on AC power loss to [Enabled]. Both of your problems will go away. no
    > more green light on after you shut down and the mouse light will go out.
    > You will also save power. Set your surge protector so that all of your
    > components will be on when you turn on the master switch. You will also
    > save the wear and tear on all the switches except the master on the surge
    > protector.Use the master switch to turn on and off your computer. I run
    > ever computer that I build like this. No problems. Hope this helps.
    > R. B.
    >
     
    Mercury, Jun 30, 2005
    #4
  5. HST

    Paul Guest

    In article <>,
    news-50.giganews.com wrote:

    > I already know now that the A8N-SLI Premium has a power LED that stays
    > lit when the computer is off and it is normal but when I shut down the
    > computer the Microsoft Intelli-mouse light stays lit, what gives and
    > how do I rectify it?
    >
    > HST
    >
    > geezzz, one problem after the other :eek:)


    For many other motherboards, the answer to this question would be
    simple. Usually an Asus motherboard has USBPWxx jumper blocks.
    The xx would be 12, 34, 56, as appropriate for the pair of USB
    ports it controls. USBPW jumper blocks allow the user to select
    powering of the USB port by the +5V source of power (which switches
    off when the computer sleeps) or by the +5VSB source of power (which
    continues to run when the computer sleeps).

    +5VSB is the one to use, when you need a USB keyboard powered, to
    do "wake by keyboard" or the like.

    Now, we come back to the A8N-SLI. Lo and behold, I see no USBPWxx
    jumper blocks! It sounds like your USB headers and rear USB ports are
    permanently wired to +5VSB, and that is why the mouse is still
    lit. On the plus side, this makes the "wakeup" function easier
    to get working (and Asus saves a whole $0.15, by not having to
    place 15 jumper pins on the board for five USBPWxx header blocks).

    I wonder if the selection of +5V or +5VSB is now made in software ?
    I'd say you have a good deal of research ahead of you, to find an
    answer to that :-(

    Phone up Asus tech support and ask them if there is an option to
    change how USB is powered. I don't see any mention of this issue
    on the Asus FAQ page. If all ten of the USB ports have been
    set up to run from +5VSB, and each one draws 500 milliamps (the
    spec max), this will crush all power supplies (most PSUs only have
    2 amps to offer on +5VSB), so if the USB powering option cannot be
    changed, this strikes me as a dumb design decision.

    http://support.asus.com.tw/faq/faq.aspx?SLanguage=en-us

    Paul
     
    Paul, Jun 30, 2005
    #5
  6. HST

    R. B. Guest

    "Mercury" <> wrote in message
    news:da0lh0$4oa$...
    > This setting is for use when you have a UPS. It means that if the system
    > is shutdown by a UPS (Power Loss) restore the system state to the prior
    > state. IE if the system was running, restart it, if the system was powered
    > off , leave it off.
    >
    > If you do not have a UPS, it is best to have it disabled as otherwise if
    > you have a rapid series of power failures you will blow up your system -
    > just like repeatedly turning the power for a light on and off will blow
    > it.
    >
    > The OP's mouse problem actually sounds like normal behaviour - the mouse
    > will go idle and turn off the light, but if it is moved it will turn on.
    > One of the Wake on xxxx settings may disable it.
    >

    When you have the surge protector off you can have a million power failures
    and it will not affect your computer
    because it if off. now power to it.
    R. B.
    >
    >
    > "R. B." <> wrote in message
    > news:eek:Dzwe.7345$dz6.6739@trnddc02...
    >>
    >> "HST" <> wrote in message
    >> news:...
    >>>I already know now that the A8N-SLI Premium has a power LED that stays
    >>> lit when the computer is off and it is normal but when I shut down the
    >>> computer the Microsoft Intelli-mouse light stays lit, what gives and
    >>> how do I rectify it?
    >>>
    >>> HST
    >>>
    >>> geezzz, one problem after the other :eek:)

    >>
    >> Go into the bios to power, then to APM Configuration and set the Restore
    >> on AC power loss to [Enabled]. Both of your problems will go away. no
    >> more green light on after you shut down and the mouse light will go out.
    >> You will also save power. Set your surge protector so that all of your
    >> components will be on when you turn on the master switch. You will also
    >> save the wear and tear on all the switches except the master on the surge
    >> protector.Use the master switch to turn on and off your computer. I run
    >> ever computer that I build like this. No problems. Hope this helps.
    >> R. B.
    >>

    >
    >
     
    R. B., Jun 30, 2005
    #6
  7. HST

    HST Guest

    On Thu, 30 Jun 2005 07:28:59 -0400, (Paul) wrotf:

    >Now, we come back to the A8N-SLI. Lo and behold, I see no USBPWxx
    >jumper blocks! It sounds like your USB headers and rear USB ports are
    >permanently wired to +5VSB, and that is why the mouse is still
    >lit. On the plus side, this makes the "wakeup" function easier
    >to get working (and Asus saves a whole $0.15, by not having to
    >place 15 jumper pins on the board for five USBPWxx header blocks).


    damn, maybe I forgot to mention that it's not a USB mouse but a PS2
    good old green round connection instead.

    HST
     
    HST, Jun 30, 2005
    #7
  8. HST

    milleron Guest

    On Thu, 30 Jun 2005 07:28:59 -0400, (Paul) wrote:

    >In article <>,
    >news-50.giganews.com wrote:
    >
    >> I already know now that the A8N-SLI Premium has a power LED that stays
    >> lit when the computer is off and it is normal but when I shut down the
    >> computer the Microsoft Intelli-mouse light stays lit, what gives and
    >> how do I rectify it?
    >>
    >> HST
    >>
    >> geezzz, one problem after the other :eek:)

    >
    >For many other motherboards, the answer to this question would be
    >simple. Usually an Asus motherboard has USBPWxx jumper blocks.
    >The xx would be 12, 34, 56, as appropriate for the pair of USB
    >ports it controls. USBPW jumper blocks allow the user to select
    >powering of the USB port by the +5V source of power (which switches
    >off when the computer sleeps) or by the +5VSB source of power (which
    >continues to run when the computer sleeps).
    >
    >+5VSB is the one to use, when you need a USB keyboard powered, to
    >do "wake by keyboard" or the like.
    >
    >Now, we come back to the A8N-SLI. Lo and behold, I see no USBPWxx
    >jumper blocks! It sounds like your USB headers and rear USB ports are
    >permanently wired to +5VSB, and that is why the mouse is still
    >lit. On the plus side, this makes the "wakeup" function easier
    >to get working (and Asus saves a whole $0.15, by not having to
    >place 15 jumper pins on the board for five USBPWxx header blocks).
    >
    >I wonder if the selection of +5V or +5VSB is now made in software ?
    >I'd say you have a good deal of research ahead of you, to find an
    >answer to that :-(
    >
    >Phone up Asus tech support and ask them if there is an option to
    >change how USB is powered. I don't see any mention of this issue
    >on the Asus FAQ page. If all ten of the USB ports have been
    >set up to run from +5VSB, and each one draws 500 milliamps (the
    >spec max), this will crush all power supplies (most PSUs only have
    >2 amps to offer on +5VSB), so if the USB powering option cannot be
    >changed, this strikes me as a dumb design decision.
    >
    >http://support.asus.com.tw/faq/faq.aspx?SLanguage=en-us
    >
    > Paul


    I have no background in electronics, so these things aren't intuitive
    for me. Please forgive me if this question is stupid, but if we're
    saying that each of 10 USB port "draws one half amp," aren't we saying
    that there's current flowing? Where is all that current going? Would
    5 amps at 5 volts, generate 25 watts worth of heat?
    Ron
     
    milleron, Jun 30, 2005
    #8
  9. HST

    Tim Guest

    *can*.
    The architectural limit is 1 amp.
    It is important not to overload a connection (obviously).
    The power jumpers that Paul mentions may do the trick.

    "milleron" <> wrote in message
    news:...
    > On Thu, 30 Jun 2005 07:28:59 -0400, (Paul) wrote:
    >
    >>In article <>,
    >>news-50.giganews.com wrote:
    >>
    >>> I already know now that the A8N-SLI Premium has a power LED that stays
    >>> lit when the computer is off and it is normal but when I shut down the
    >>> computer the Microsoft Intelli-mouse light stays lit, what gives and
    >>> how do I rectify it?
    >>>
    >>> HST
    >>>
    >>> geezzz, one problem after the other :eek:)

    >>
    >>For many other motherboards, the answer to this question would be
    >>simple. Usually an Asus motherboard has USBPWxx jumper blocks.
    >>The xx would be 12, 34, 56, as appropriate for the pair of USB
    >>ports it controls. USBPW jumper blocks allow the user to select
    >>powering of the USB port by the +5V source of power (which switches
    >>off when the computer sleeps) or by the +5VSB source of power (which
    >>continues to run when the computer sleeps).
    >>
    >>+5VSB is the one to use, when you need a USB keyboard powered, to
    >>do "wake by keyboard" or the like.
    >>
    >>Now, we come back to the A8N-SLI. Lo and behold, I see no USBPWxx
    >>jumper blocks! It sounds like your USB headers and rear USB ports are
    >>permanently wired to +5VSB, and that is why the mouse is still
    >>lit. On the plus side, this makes the "wakeup" function easier
    >>to get working (and Asus saves a whole $0.15, by not having to
    >>place 15 jumper pins on the board for five USBPWxx header blocks).
    >>
    >>I wonder if the selection of +5V or +5VSB is now made in software ?
    >>I'd say you have a good deal of research ahead of you, to find an
    >>answer to that :-(
    >>
    >>Phone up Asus tech support and ask them if there is an option to
    >>change how USB is powered. I don't see any mention of this issue
    >>on the Asus FAQ page. If all ten of the USB ports have been
    >>set up to run from +5VSB, and each one draws 500 milliamps (the
    >>spec max), this will crush all power supplies (most PSUs only have
    >>2 amps to offer on +5VSB), so if the USB powering option cannot be
    >>changed, this strikes me as a dumb design decision.
    >>
    >>http://support.asus.com.tw/faq/faq.aspx?SLanguage=en-us
    >>
    >> Paul

    >
    > I have no background in electronics, so these things aren't intuitive
    > for me. Please forgive me if this question is stupid, but if we're
    > saying that each of 10 USB port "draws one half amp," aren't we saying
    > that there's current flowing? Where is all that current going? Would
    > 5 amps at 5 volts, generate 25 watts worth of heat?
    > Ron
     
    Tim, Jul 1, 2005
    #9
  10. > Phone up Asus tech support and ask them if there is an option to
    > change how USB is powered. I don't see any mention of this issue
    > on the Asus FAQ page. If all ten of the USB ports have been
    > set up to run from +5VSB, and each one draws 500 milliamps (the
    > spec max), this will crush all power supplies (most PSUs only have
    > 2 amps to offer on +5VSB), so if the USB powering option cannot be
    > changed, this strikes me as a dumb design decision.


    I believe there is a BIOS setting that controls this - at least I have
    not noticed any USB devices remaining powered with the system off on my
    board which has all the wakeup options disabled. I don't know about PS/2
    devices as the poster is apparently using, however.

    --
    Robert Hancock Saskatoon, SK, Canada
    To email, remove "nospam" from
    Home Page: http://www.roberthancock.com/
     
    Robert Hancock, Jul 1, 2005
    #10
  11. "milleron" <> wrote in message
    news:...
    > On Thu, 30 Jun 2005 07:28:59 -0400, (Paul) wrote:
    >
    >>In article <>,
    >>news-50.giganews.com wrote:
    >>
    >>> I already know now that the A8N-SLI Premium has a power LED that stays
    >>> lit when the computer is off and it is normal but when I shut down the
    >>> computer the Microsoft Intelli-mouse light stays lit, what gives and
    >>> how do I rectify it?
    >>>
    >>> HST
    >>>
    >>> geezzz, one problem after the other :eek:)

    >>
    >>For many other motherboards, the answer to this question would be
    >>simple. Usually an Asus motherboard has USBPWxx jumper blocks.
    >>The xx would be 12, 34, 56, as appropriate for the pair of USB
    >>ports it controls. USBPW jumper blocks allow the user to select
    >>powering of the USB port by the +5V source of power (which switches
    >>off when the computer sleeps) or by the +5VSB source of power (which
    >>continues to run when the computer sleeps).
    >>
    >>+5VSB is the one to use, when you need a USB keyboard powered, to
    >>do "wake by keyboard" or the like.
    >>
    >>Now, we come back to the A8N-SLI. Lo and behold, I see no USBPWxx
    >>jumper blocks! It sounds like your USB headers and rear USB ports are
    >>permanently wired to +5VSB, and that is why the mouse is still
    >>lit. On the plus side, this makes the "wakeup" function easier
    >>to get working (and Asus saves a whole $0.15, by not having to
    >>place 15 jumper pins on the board for five USBPWxx header blocks).
    >>
    >>I wonder if the selection of +5V or +5VSB is now made in software ?
    >>I'd say you have a good deal of research ahead of you, to find an
    >>answer to that :-(
    >>
    >>Phone up Asus tech support and ask them if there is an option to
    >>change how USB is powered. I don't see any mention of this issue
    >>on the Asus FAQ page. If all ten of the USB ports have been
    >>set up to run from +5VSB, and each one draws 500 milliamps (the
    >>spec max), this will crush all power supplies (most PSUs only have
    >>2 amps to offer on +5VSB), so if the USB powering option cannot be
    >>changed, this strikes me as a dumb design decision.
    >>
    >>http://support.asus.com.tw/faq/faq.aspx?SLanguage=en-us
    >>
    >> Paul

    >
    > I have no background in electronics, so these things aren't intuitive
    > for me. Please forgive me if this question is stupid, but if we're
    > saying that each of 10 USB port "draws one half amp," aren't we saying
    > that there's current flowing? Where is all that current going? Would
    > 5 amps at 5 volts, generate 25 watts worth of heat?
    > Ron

    Somewhere yes.
    However, available power doesn't have to be 'drawn'. A USB port, is
    allowed to draw 100mA max, then the OS is allowed to 'authorise' up to
    500mA to be drawn by a device. Things like USB 2.5" HD's need all of this,
    while things like mice only draw a few mA. Most systems don't implement
    the originally envisaged 'switching', to actually change the power
    available, instead just having a relatively simple self resetting fuse on
    the USB power line.
    The power supply on your computer is probably able to deliver well over
    300W, and if it was delivering this, it'd all end up as heat somewhere
    (most in the HD's, video card, processor etc.), but typically most
    computers 'only' draw about 120W, in 'normal' operation.
    Now the poster was pointing out that if all USB ports remain powered off
    the standby line, and all were in use, with devices potentially able to
    draw the maximum current, the supply would need to be able to deliver 5A
    just to feed these devices.
    Leaving power on some ports, is 'normal', snce it is required if you have
    a USB keyboard/mouse, and want to implement 'keyboard' wake-up from
    suspend. Similarly, modem wake-up, if using a USB modem, requires this.
    The normal 'practice', is to have just two of the ports connected to the
    +5SB line, and the rest from the 'main' supply line. Some motherboards go
    a little further, and allow you to 'jumper' this option, while others have
    it software enabled, if these wake-up options are selected in the BIOS.
    For some 'unfathomable' reason, On the particular boards concerned, Asus
    appear to have elected to control the power from the BIOS option setting
    whether the machine automatically wakes up when power is restored, rather
    than the option controlling any USB 'wake-up'....

    Best Wishes
     
    Roger Hamlett, Jul 1, 2005
    #11
  12. HST

    jroc Guest

    On Fri, 01 Jul 2005 10:53:51 GMT, "Roger Hamlett"
    <> managed to one finger type the following:

    All I know is...that I have a USB Wireless Optical Mouse..and when I power down
    the "transmitter" powers off....but the Mouse goes into 'standby'..faint red
    glow.....Only thing that might be the solution....is check in the "Device"
    manager under Universal Serial Bus Controllers...and 'double click' each root
    hub and then go to 'power management and check the box 'allow the computer to
    turn off this device to save power'....also when you double click the USB Root
    Hub to view the properties...under the 'Power' tab will list any devices on that
    hub....for instance under one of my root hubs "power tab" is listed "Microsoft
    USB Wireless Mouse (IntelliPoint) and HP Scanjet 8200.
    "De Oppresso Liber"
    From Oppression Liberate

    jroc® 7th Special Forces Ft.Bragg N.C 18/Bravo
    ****only thing easy in life is failure****
    *******so get tough*******
     
    jroc, Jul 1, 2005
    #12
  13. HST

    milleron Guest

    On Fri, 01 Jul 2005 10:53:51 GMT, "Roger Hamlett"
    <> wrote:

    >
    >"milleron" <> wrote in message
    >news:...
    >> On Thu, 30 Jun 2005 07:28:59 -0400, (Paul) wrote:
    >>
    >>>In article <>,
    >>>news-50.giganews.com wrote:
    >>>
    >>>> I already know now that the A8N-SLI Premium has a power LED that stays
    >>>> lit when the computer is off and it is normal but when I shut down the
    >>>> computer the Microsoft Intelli-mouse light stays lit, what gives and
    >>>> how do I rectify it?
    >>>>
    >>>> HST
    >>>>
    >>>> geezzz, one problem after the other :eek:)
    >>>
    >>>For many other motherboards, the answer to this question would be
    >>>simple. Usually an Asus motherboard has USBPWxx jumper blocks.
    >>>The xx would be 12, 34, 56, as appropriate for the pair of USB
    >>>ports it controls. USBPW jumper blocks allow the user to select
    >>>powering of the USB port by the +5V source of power (which switches
    >>>off when the computer sleeps) or by the +5VSB source of power (which
    >>>continues to run when the computer sleeps).
    >>>
    >>>+5VSB is the one to use, when you need a USB keyboard powered, to
    >>>do "wake by keyboard" or the like.
    >>>
    >>>Now, we come back to the A8N-SLI. Lo and behold, I see no USBPWxx
    >>>jumper blocks! It sounds like your USB headers and rear USB ports are
    >>>permanently wired to +5VSB, and that is why the mouse is still
    >>>lit. On the plus side, this makes the "wakeup" function easier
    >>>to get working (and Asus saves a whole $0.15, by not having to
    >>>place 15 jumper pins on the board for five USBPWxx header blocks).
    >>>
    >>>I wonder if the selection of +5V or +5VSB is now made in software ?
    >>>I'd say you have a good deal of research ahead of you, to find an
    >>>answer to that :-(
    >>>
    >>>Phone up Asus tech support and ask them if there is an option to
    >>>change how USB is powered. I don't see any mention of this issue
    >>>on the Asus FAQ page. If all ten of the USB ports have been
    >>>set up to run from +5VSB, and each one draws 500 milliamps (the
    >>>spec max), this will crush all power supplies (most PSUs only have
    >>>2 amps to offer on +5VSB), so if the USB powering option cannot be
    >>>changed, this strikes me as a dumb design decision.
    >>>
    >>>http://support.asus.com.tw/faq/faq.aspx?SLanguage=en-us
    >>>
    >>> Paul

    >>
    >> I have no background in electronics, so these things aren't intuitive
    >> for me. Please forgive me if this question is stupid, but if we're
    >> saying that each of 10 USB port "draws one half amp," aren't we saying
    >> that there's current flowing? Where is all that current going? Would
    >> 5 amps at 5 volts, generate 25 watts worth of heat?
    >> Ron

    >Somewhere yes.
    >However, available power doesn't have to be 'drawn'. A USB port, is
    >allowed to draw 100mA max, then the OS is allowed to 'authorise' up to
    >500mA to be drawn by a device. Things like USB 2.5" HD's need all of this,
    >while things like mice only draw a few mA. Most systems don't implement
    >the originally envisaged 'switching', to actually change the power
    >available, instead just having a relatively simple self resetting fuse on
    >the USB power line.
    >The power supply on your computer is probably able to deliver well over
    >300W, and if it was delivering this, it'd all end up as heat somewhere
    >(most in the HD's, video card, processor etc.), but typically most
    >computers 'only' draw about 120W, in 'normal' operation.
    >Now the poster was pointing out that if all USB ports remain powered off
    >the standby line, and all were in use, with devices potentially able to
    >draw the maximum current, the supply would need to be able to deliver 5A
    >just to feed these devices.
    >Leaving power on some ports, is 'normal', snce it is required if you have
    >a USB keyboard/mouse, and want to implement 'keyboard' wake-up from
    >suspend. Similarly, modem wake-up, if using a USB modem, requires this.
    >The normal 'practice', is to have just two of the ports connected to the
    >+5SB line, and the rest from the 'main' supply line. Some motherboards go
    >a little further, and allow you to 'jumper' this option, while others have
    >it software enabled, if these wake-up options are selected in the BIOS.
    >For some 'unfathomable' reason, On the particular boards concerned, Asus
    >appear to have elected to control the power from the BIOS option setting
    >whether the machine automatically wakes up when power is restored, rather
    >than the option controlling any USB 'wake-up'....
    >
    >Best Wishes
    >

    Thanks. I couldn't imagine that a computer in Standby would be
    "drawing" anywhere near 5 amps on the USB ports since there's
    essentially nothing being powered in that state.

    Ron
     
    milleron, Jul 1, 2005
    #13
  14. HST

    Paul Guest

    In article <>,
    wrote:

    > On Thu, 30 Jun 2005 07:28:59 -0400, (Paul) wrote:
    >
    > >
    > >Phone up Asus tech support and ask them if there is an option to
    > >change how USB is powered. I don't see any mention of this issue
    > >on the Asus FAQ page. If all ten of the USB ports have been
    > >set up to run from +5VSB, and each one draws 500 milliamps (the
    > >spec max), this will crush all power supplies (most PSUs only have
    > >2 amps to offer on +5VSB), so if the USB powering option cannot be
    > >changed, this strikes me as a dumb design decision.
    > >
    > >http://support.asus.com.tw/faq/faq.aspx?SLanguage=en-us
    > >
    > > Paul

    >
    > I have no background in electronics, so these things aren't intuitive
    > for me. Please forgive me if this question is stupid, but if we're
    > saying that each of 10 USB port "draws one half amp," aren't we saying
    > that there's current flowing? Where is all that current going? Would
    > 5 amps at 5 volts, generate 25 watts worth of heat?
    > Ron


    As another poster pointed out, I was saying what would
    happen in a pathological test case. A USB port can support up to
    a 500 milliamp load. Drawing more current than that, causes the
    Polyfuse in the circuit to open, shutting off bus power. By
    default from the factory, normally the USBPWxx jumper blocks are
    set so that the USB headers and connector stack get their power
    from +5V. Since your power supply has 20 amps or more available
    on that output rail, if the pathological test case arose, the
    power supply could handle it.

    If a user wanted a "Wake on USB" keyboard and mouse scenario,
    they would change only the USBPWxx jumper block for the jacks
    used for the keyboard and mouse. Usually the PS/2 connectors have
    a similar option, if you wanted "Wake on PS/2" keyboard and mouse.
    The rest of the jacks would remain powered from +5V in that case,
    meaning there is little chance of exceeding the power supply's
    limited amount of +5VSB.

    In terms of power consumed when the computer sleeps, your PSU has
    a limited output on +5VSB. The label on the side might list a
    number like 2 amps or so. Only if you have a lot of devices that
    remain powered when the computer sleeps, would you get close to
    the limit. Since some power supplies are only 50% efficient in
    the sleeping state, you could see up to 20 watts load at the
    wall socket. Note that it is hard to measure this power accurately,
    so if you want to do such a measurement, I recommend using a
    "Kill-a-watt" type measuring device, combined with a PSU that
    uses "Active PFC", as the waveform on an active PFC (power factor
    corrected) power supply is close to sinusoidal, and makes getting
    an accurate measurement much more likely. I've noticed my $400 meter
    doesn't like the waveform from my non-PFC PSU, and gives ridiculous
    readings on the AC side. Non-sinusoidal current waveforms tend to
    exceed the bandwidth of the analog path in the metering device
    (a typical good meter might only be capable of responding out to
    50KHz or so - many meters will be worse than that).

    Has anyone verified when the USB power is shut off ? Is there
    a BIOS setting that works or not ? I can, for example, see
    three Polyfuses next to the standby LED, and the proximity of
    those parts suggests to me, that +5VSB is connected direct to
    the Polyfuse. Normally, the powering path would look like this
    on an Asus board:
    USBPW12 "Typical Asus board"
    (header)
    +5VSB (always powered) ---X USB_jack_1
    X---Polyfuse-+---+--X 5V
    +5V (only when running) --X | | X D+
    (filter --- | X D-
    cap) --- | X GND
    | |
    GND | USB_jack_2
    +--X 5V
    X D+
    X D-
    X GND

    I'm suspecting the A8N-SLI looks more like this, and it would
    be nice to have someone confirm or deny that it works like this:

    A8N-SLI Family hypothetical model (assumes no BIOS option)

    USB_jack_1
    +5VSB (always powered)---Polyfuse-+---+--X 5V
    | | X D+
    (filter --- | X D-
    cap) --- | X GND
    | |
    GND | USB_jack_2
    +--X 5V
    X D+
    X D-
    X GND


    A8N-SLI Family hypothetical model (assumes a working BIOS option).
    (Here, either transistor #1 or #2 is turned on by BIOS code. I
    don't see any chips or discrete transistors on the board, located
    to do something like this. This would not be a good function to
    integrate into the Southbridge either.)

    +5VSB (always powered) ---+
    |
    Series-pass transistor #1
    |
    | USB_jack_1
    X---Polyfuse-+---+--X 5V
    | | | X D+
    | (filter --- | X D-
    Series-pass transistor #2 cap) --- | X GND
    | | |
    +5V (only when running) --+ GND | USB_jack_2
    +--X 5V
    X D+
    X D-
    X GND

    In this Intel reference schematic, on PDF page 84, they use a small
    8 pin device SI4501 to switch between +5V and +5VSB for a USB port.
    Perhaps an Intel BIOS has an option to select one or the other...

    ftp://download.intel.com/design/chipsets/schematics/25281202.pdf (9MB!)

    Example of a small device suitable for switching USB power sources.
    This is likely too expensive for Asus's tastes.

    http://www.vishay.com/doc?70934 (SI4501)

    Paul
     
    Paul, Jul 2, 2005
    #14
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