Keyboard won't wake computer from Sleep mode

Discussion in 'PC Hardware' started by Rebel1, Jan 14, 2014.

  1. Rebel1

    Rebel1 Guest

    I have the monitor and the desktop computer set to sleep after 2 hours
    of disuse; the hard drive goes off after 20 minutes.

    Pressing any key on the wired keyboard (PS2 connector) will not wake the
    system. Clicking on the wireless USB mouse will wake it. Shouldn't the
    keyboard also wake it?

    Windows 8.


    Rebel1, Jan 14, 2014
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  2. Rebel1

    Paul Guest

    To make that work, you have to look in two places.

    Sometimes the BIOS has settings. PME needs to be
    enabled for PCI (NIC cards) and USB perhaps. And PS/2
    has a separate section, where you can specify the
    key sequence used. Not all chips have the same
    options for this.

    And the Device Manager definitely has settings.
    "Allow This Device..." thing.

    PS/2 connects to the SuperI/O chip. And in some cases,
    you get to specify a "key sequence" on PS/2. Some
    of the BIOS are not set up or designed, to trigger
    on just a single key press of <any> key. Their design
    idea is to prevent accidental waking (cat steps on keyboard).

    Also, any peripheral intended to wake the computer, needs power.
    Older motherboards, had a 1x3 jumper block, which selected
    +5V or +5VSB as a power source. The former would prevent
    wake from sleep. The latter leaves things like the PS/2 keyboard,
    powered while the computer sleeps. On modern computers, they
    no longer bother with the 1x3 header concept, and just run all
    the ports from the +5VSB supply. And thus, a modern computer
    doesn't have to worry about the contents of this paragraph.

    So have a look in the BIOS, and also in the Device Manager.
    You'll have it working in no time :)

    Paul, Jan 14, 2014
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  3. Rebel1

    Rebel1 Guest

    Thanks, Paul, for the solution.

    I went to DM, clicked on Keyboard, then on standard PS/2 keyboard. That
    brought up the Keyboard Properties dialog box. The Power Management tab
    has a box called "Allow this device to wake the computer." Once I
    checked the box, the problem was solved.

    Out of curiosity, next time I booted the computer I went into the BIOS.
    There is a setting called "Power on From S5 by PS/2 KB/MS." It was
    disabled. (Asus M3A76-CM motherboard.) I left it that way since the
    problem was solved using Device Manager.

    As I thought more about my sleep settings of 20 minutes for the hard
    drive and 2 hours for the computer and monitor, they now don't make any
    sense. With the hard drive off after 20 minutes, what else would occur
    in the computer after 2 hours to enter the Sleep state? Does it ever
    make sense to have these three settings at different times? Possibly a
    screensaver for the LCD monitor after some period of idleness, but I'm
    not sure that this needed these days to prevent monitor damage.

    This is a desktop computer, so I'm not trying to conserve battery power
    but merely AC power use after a idle period. I don't have any idea of
    what the consumption is when in the normal mode vs sleep mode.

    Thanks, again.

    Rebel1, Jan 15, 2014
  4. Rebel1

    Rebel1 Guest

    FWIW, it takes two keyboard taps to get the system going. The first
    activates the computer, the second (a few seconds later) wakes the
    monitor. This is okay as far as I'm concerned.
    Rebel1, Jan 15, 2014
  5. Rebel1

    Paul Guest

    Turning off the monitor, saves the life of the backlight. That's
    the purpose on an LCD.

    An LCD with CCFL lighting in back, lasts for around 25,000 hours.
    The inverter that powers the CCFL, lasts for less than that. Sometimes
    a quite short time (couple years on a cheap monitor). The inverter
    is variable in design quality, with some good ones and a lot of bad ones
    being used.

    Even a LED monitor has a limited lifespan. LEDs, the light output
    diminishes with age. LED death is defined in terms of the light
    declining to a certain level. While a LED is solid-state, it
    still probably doesn't hurt to turn off the screen when not in usage.
    At least with a LED, it might not turn brown the way a CCFL does
    when it gets old.

    Paul, Jan 15, 2014
  6. Rebel1

    Rebel1 Guest

    Any specific recommendations for computer, monitor and hard drive times
    to enter Sleep?


    Rebel1, Jan 15, 2014
  7. Rebel1

    Paul Guest

    20 minutes for hard drive and 2 hours for monitor would be fine with me.

    I don't like a monitor falling asleep while I'm in front of it. But
    if I walk away from a computer and don't come back for 12 hours and
    the screen is still lit, that's a waste. So 2 hours for screen would
    suit me.

    20 minutes would be OK for hard drive. The hard drive is rated for
    anywhere from 50,000 to 300,000 spin-up cycles. Your 20 minute
    choice would be 72 cycles a day, max. In an "unlucky day", you're
    only likely to encounter a handful of cycles, not the whole 72 of them.
    That probably isn't a danger to hard drive life. You would have to
    carefully arrange your usage pattern of the computer, to actually
    get it to spin down all 72 times.

    There were some drives in USB enclosures that were doing 400 cycles
    per day, and they seem to have survived it. Seagate and WD do that
    to their "book" form factor USB drives, for thermal control, rather
    than some "conservation" reason. A hard drive within a computer
    case, you probably have better drive cooling in there, than a
    USB hard drive case with no fan inside.

    Setting the computer to sleep after two hours, I've never bothered
    with that. I hibernate the computer manually when I'm done with it.
    I've had 7ZIP runs that lasted for days, and so the computer is
    just left running until those are done.

    Paul, Jan 15, 2014
  8. Rebel1

    Rebel1 Guest

    Thanks for your comments, Paul.

    Rebel1, Jan 16, 2014
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