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computer wont boot after power outage

Discussion in 'Hardware' started by paul, Nov 13, 2003.

  1. paul

    paul Guest

    I live in an old building in boston which at times can be prone to
    power ouitages if we are using to much electricity. Last night we had
    an outage, when the power did come back on everyone was able to turn
    their computers back on except for me. Everything that is plugged into
    my surge protector is able to turn on except for my computer, but the
    standby light on the mb is on as well as the link light on my nic
    card. When i went to go hit the power button to turn it on again (this
    ussually goes off with out any problem, we get these surges every once
    in a while) the fans twitched and then nothing. I pushed the power
    button on and off repeatedly, changed outlets, but to no avail. I
    built the machine so i know the computer well , i just need some
    advice as to where i should start troubleshooting or if any of you
    have experienced this problem.

    **Interesting note: all of my roomates computers came back up with no
    problem
     
    paul, Nov 13, 2003
    #1
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  2. paul

    w_tom Guest

    By your own admission, you did not have a power surge. Did 330+ volts
    pass through everything in your flat? If so, then you would be
    listing other damaged items. You had an unexpected power loss. With
    so many promoting ineffective surge protectors, you would think surges
    are a daily occurance. Surges occur typically once every eight years.

    But you do have a problem. Start with the simple stuff. Establish
    the integrity of a foundation before analyzing the building.
    Foundation consists of power swtich, power supply, and power supply
    control logic on motherboard. First remove power plug from wall; then
    reconnect. This will reset a protection feature in the control logic.
    Does it power up?

    Next get the 3.5 digit multimeter. Measure for 5 volts on the
    purple wire from power supply to motherboard. This is power for the
    control logic. No 5 volts most likely means a power supply failure.

    Next monitor the green control logic wire. It should be above 2.4
    volts when powered off and should drop to near zero volts when power
    switch is pressed. Does this happen?

    If it does happen, then check essential voltages either while the
    green wire remains at zero volts, or when power switch is pressed.
    Essential voltages are the red, orange, and yellow wires. Voltages
    should rise to 3.3., 5, and 12 - and remain stable.

    If any one voltage comes up and drops, then there is a problem with
    something connected to the other voltages. Find the voltage that does
    not obtain its required reading.

    That 3.5 digit multimeter is as essential as your screwdriver. So
    inexpensive, so necessary, and so ubiquitous as to be sold in Home
    Depot, Lowes, Sears, and Radio Shack. As demonstrated, you don't fix
    anything until the problem is located. And with computers, problems
    are quickly isolated with some simple tools and basic knowledge.

    If power supply voltage do obtain correct values, then move on to
    reset BIOS. Simple procedure. However don't try to reset BIOS is
    power supply voltages are not stable. You might complicate the
    problem.
     
    w_tom, Nov 13, 2003
    #2
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  3. paul

    DaveW Guest

    The easiest place to start is to try replacing the power supply. If that
    isn't it you may have a fried motherboard.
     
    DaveW, Nov 14, 2003
    #3
  4. paul

    w_tom Guest

    In the time it takes to swap a power supply, that other (and superior)
    method of finding the problem could be completely executed.
    Furthermore, one has to spend lots of time purchasing a power supply -
    not even knowing it is the problem.

    When one recommends immediately replacing a power supply, then run.
    He is the classic hack who never bothered to learn how things work.
    Wildly replacing parts is called shotgunning. Shotgunning is also
    performed by scam car mechanics who never learned.

    The easiest method is also the fastest method - using that 3.5 digit
    multimeter.
     
    w_tom, Nov 14, 2003
    #4
  5. paul

    paul Guest

    thanks for all the advice, luckily enough i managed to get a power
    supply from work for free,...i am also going to buy a multimeter from
    radio shack today, i think w_tom has a good point about finding out
    how things work (im not always going to be able to get parts for free
    , and that might not even be the problem anyway!!!)Im going to try and
    trouble shoot this thing tonight,.....ill keep you guys posted on how
    it turns out

    paul


    (w_tom) wrote in message
     
    paul, Nov 17, 2003
    #5
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