A8N5X won't power up.

Discussion in 'Asus' started by Randy Davis, Jul 4, 2006.

  1. Randy Davis

    Randy Davis Guest

    I have an A8N5X that was running fine. All of the sudden it shut off and now
    will not power up. The onboard power light is on.

    I'm using Corsair D400 member (2x512)
    AMD Athlon 64 3200+
    EVGA N 6600 GT with 128 meg
    PowerMax Assassin 500W SATA power supply

    I'm looking for suggestions as to why it will not power up. I get nothing
    when I hit the power switch.

    Randy Davis, Jul 4, 2006
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  2. Randy Davis

    Liquid Guest

    Maybe use a volmeter and check your power supply never done it but
    would think they would show voltage. Not sure how you would check the
    draw of current Paul might know. Check the power cable/on button cable
    maybe it got loose. Not really sure with the info you gave maybe
    something failed. Wish I could help more.

    Best Regards,
    Liquid, Jul 5, 2006
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  3. Randy Davis

    BC Guest

    Dear Randy,

    I think the key word there is "Assassin": I think your power supply is

    Here is a Powermax 400W unit for $12.99:


    Inexpensive is good, but, cheaply built and cheap is not necessarily good...

    Actually, just found the "assassin":



    *17A* on the 12v line:


    "The total Watts is important but the Total Amperage Available on the
    +12V Rail(s) is the most important, followed by the +5V amperage and
    then the +3.3V amperage. Because of the increased power consumption of
    the new high-power video cards the recommended minimum for +12V is
    *26A*, for SLI 35A."

    Key word: "hit" (assassin). It's dead.

    This PSU is good:


    I have an A8N5X, 3700 CPU, 6600GT, and use this PSU, works great: a
    Seasonic 430:


    Enermax or Fortron: also good:


    Antec: OK, seems like they have had some issues of late, but I have had
    good luck with them.

    OCZ: think "assassin", as in killing your mobo and hard drive. Avoid
    like the PowMax.

    Hey, here is the PowMax on Newegg:


    An 85% "very poor" grade....ouch.

    Here is their 580W "demon" unit reviewed:

    "15 Months then Poof

    Pros: It was cheap

    Cons: It died after 15 months. Luckily I was in the room when it blew.
    I still have the smell in the room. Glad my house didn't burn down."

    So, replace PSU with a quality unit, and hope the "Assassin" didn't take
    anything with it on its suicide mission.


    BC, Jul 5, 2006
  4. Randy Davis

    Paul Guest

    When you go to use the power button on the front of the case,
    does the green LED on the motherboard blink off ? The green
    LED should stay on steady, no matter what. If there is any
    blinking of the green LED, the power supply is toast.

    Similarly, if the fans twitch for just a fraction of a second,
    when you use the front power switch, it could mean there is an
    overload somewhere. Or if the power supply has developed an
    internal weakness, it could interpret the normal computer loading,
    as an overload condition. Thus you'd get the twitch.

    Measuring voltages is only practical, if a power supply will stay
    running. Since some power supplies have a minimum loading spec
    for some of their rails, it isn't always a good idea to run them
    no load. I have a small load test box, but pricing that out
    a few days ago for someone, it would likely cost about $50 to
    whip one together, with a representative load for the PSU.

    Measuring current draw is also difficult to do with a hardware
    store multimeter. Ordinary metering requires that you connect the
    red and black leads of the meter, in series with the load.
    That means buying an ATX 20pin to 20pin extension cable, and
    cutting a wire in the cable in two, then connecting the ammeter
    leads to the two ends. You need to use the 10 amp range holes
    on the meter, and set the meter to DC amps. You cannot disturb
    the leads while the computer is running, and can only change
    measurement configurations after the computer is shut down.
    If the leads of the meter fall off, or the wire you are
    measuring goes open circuit, then that might hurt something.
    That sucks as a way to measure how much current is there, and
    it would take forever to check all 20 wires.

    In the case of a detected overload, the excessive current flow
    will only exist for about 0.05 seconds after you press the
    power button. You would need a meter with a "peak hold" capability
    and a high sampling rate, to "catch" such an overload.

    I use a clamp-on AC/DC ammeter, that measures the magnetic
    field around a wire. If the ATX power supply has an unsheathed
    cable, so you can grab the individual wires, then it only takes
    a few seconds per current measurement, and you can move the
    clamp jaws from wire to wire, while the computer is still
    running. But a meter like that will cost about $250, and stripped
    to its essentials, maybe someone could make one for $100 if they
    wanted to. Not quite the same thing as a $30 hardware store
    multimeter. (While my meter does have a peak hold function, I'm
    not sure it would be quick enough to catch a 0.05 second overload.
    The basic detector has the bandwidth for the measurement, but
    the metering circuit is not designed for short events like that.)

    My standard advice for your symptoms: borrow a spare power supply
    and test with it. Much easier than trying to do measurements, and
    if you are lucky, the spare will be all that is needed to get you
    on the road again. If you are still stuck, then more work will be

    Is there any "burned" smell around the equipment ? Maybe the
    power supply has already tried to tell you something.

    Paul, Jul 5, 2006
  5. Randy Davis

    Randy Davis Guest

    A new power supply fixed it right up.

    Randy Davis
    Randy Davis, Jul 11, 2006
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