Power surge damage

Discussion in 'Asus' started by John, May 15, 2011.

  1. John

    John Guest

    My daughter had a power surge bad enough to get through the surge
    protector and hit the computer. After the surge, the computer would
    boot but had no internet or USB. Thinking that the mobo was fried,
    she replaced it and that seemd to cure the problem. But a day later,
    ir came back -- no internet, no USB. If she turns it off for a while
    and back on, it's okay, at least for a while.

    She's asking my opinion of what else could be wrong and I'm thinking
    it sounds like PSU. Do others agree? If not, then what else might it
    be?


    Reply-to address is real
    -- John
     
    John, May 15, 2011
    #1
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  2. John

    Paul Guest

    John wrote:
    > My daughter had a power surge bad enough to get through the surge
    > protector and hit the computer. After the surge, the computer would
    > boot but had no internet or USB. Thinking that the mobo was fried,
    > she replaced it and that seemd to cure the problem. But a day later,
    > ir came back -- no internet, no USB. If she turns it off for a while
    > and back on, it's okay, at least for a while.
    >
    > She's asking my opinion of what else could be wrong and I'm thinking
    > it sounds like PSU. Do others agree? If not, then what else might it
    > be?
    >
    >
    > Reply-to address is real
    > -- John


    One question would be about the surge itself. Were other devices in the
    house affected ? Was the surge protector damaged ? Some surge protectors
    have a status LED that lights up when the surge protector itself is fried.
    (Of several I own, one has the LED.)

    Naturally, the power supply is the first thing to feel the effects of the
    surge. And with the limited feedback range on the control loop, it's also
    possible the overvoltage could be transferred through to the outputs.
    (The transformer within the power supply likely has a breakdown rating
    of more than 1100 volts, and lightning could easily jump across there
    and go right into the DC outputs. The sticker on the ATX supply that
    says "hi pot tested", verifies that the transformer can take at
    least 1100 volts across the insulation inside it. That is intended to
    stop certain kinds of power company issues going straight into the PC,
    but can't stop lighting, because nothing stops a direct lightning
    hit.)

    Now, say the primary rails 3.3V, 5V, 12V are out of spec. The power supply
    itself has a signal Power_Good on the main cable, which is supposed to
    detect when the voltages are close to the final values, at start up. The
    motherboard won't start running unless there is Power_Good asserted by
    the power supply. The motherboard stays in reset, until Power_Good is
    asserted. If the rails were substantially low, then the computer would
    sit there with a black screen, fans running.

    To have your current symptoms then, you'd need a rail to drop to a low
    voltage, Power_Good to remain asserted, and other circuits on the motherboard
    to still "feed good enough" for the computer itself not to crash. Which
    seems a bit strange.

    I think there is more to it than power supply, but swapping in another
    supply for a test would be a good thing to try. If someone has a
    multimeter handy, they can take the side off the PC, clip the black
    ground lead to a screw on the I/O plate on the back of the computer,
    then take the red lead, and probe the exposed metal within each hole
    of the nylon shell of the main connector. In rough round numbers, the
    primary rails should be within 5% tolerance. So if you probed where the
    yellow wire went into the nylon shell of the PSU connector, the meter
    would read 12.00 on the 20V range when you touched the metal inside where
    the yellow wire meets the motherboard. A 5% tolerance, means any value
    between 11.4V and 12.6V is acceptable.

    Power supply specs, oldest to newest... Pinout tables...

    http://web.archive.org/web/20030424...org/developer/specs/atx/ATX_ATX12V_PS_1_1.pdf (page 27)

    http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf (page 30)

    http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf (page 37)

    The rails used for Internet and USB, could be different as well. USB
    at the interface pads, may be using the +5VSB rail. And if that was
    out of spec enough, the PC would shut off because there isn't enough
    voltage to run supervision logic. The Internet would rely on several voltages,
    such as 3.3V or an onboard regulator that converts 3.3V into an even
    lower voltage for the core logic of the LAN chip. (Many LAN chips use
    two rails, one rail being internal on the motherboard.) And I really have
    to wonder why the PC is still running, if multiple rails are out of
    whack. You'd think something would crash or shut down.

    Another question you'd have to ask, is whether the hard drive(s) were
    damaged. The hard drive has surge protection devices on +5V and +12V.
    A sustained overvoltage on either rail, causes the surge protector
    device on the drive to get burned. Such a situation may arise on a
    computer with a 250W Bestec brand supply, and a failure there
    comes from the supply output rising on its own, to a higher than
    normal value.

    I'm not liking the symptoms here, because I don't have a good explanation
    for them. You can try another supply, especially if you don't have
    a multimeter. Swapping is easy to do, even for a novice, as long as
    they take pictures with a digital camera and put everything back the
    way they found it. If you aren't there personally to help, you can
    use pictures from this web page, to aid in discussions about
    connectors (such as "why are these Molex 1x4 connectors on the
    hard drives, so hard to remove" :) ). When removing the Molex 1x4
    from a drive, you should use your fingers, as attempting to apply
    tools to it, the tools slip off. Wiggling it is what I attempt
    to do. Modern supplies have a compression section on either
    side of the Molex, which when compressed, pushes against the
    drive and eases the connector out. But the older connectors
    don't have that feature, and it takes a fair bit of finger
    strength to get them to budge.

    http://www.playtool.com/pages/psuconnectors/connectors.html

    (Hard on the fingers...)
    http://www.playtool.com/pages/psuconnectors/peripheralpic.jpg

    Good luck, and post back if the symptoms aren't resolved. I
    feed there is more at work here than just supply. Maybe a
    USB device is damaged and overloading something ? With all
    excess USB devices disconnected, does the LAN still run ?

    Paul
     
    Paul, May 16, 2011
    #2
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  3. John

    john Guest

    On Sun, 15 May 2011 19:43:00 -0400, Paul <> wrote:

    >John wrote:
    >> My daughter had a power surge bad enough to get through the surge
    >> protector and hit the computer. After the surge, the computer would
    >> boot but had no internet or USB. Thinking that the mobo was fried,
    >> she replaced it and that seemd to cure the problem. But a day later,
    >> ir came back -- no internet, no USB. If she turns it off for a while
    >> and back on, it's okay, at least for a while.
    >>
    >> She's asking my opinion of what else could be wrong and I'm thinking
    >> it sounds like PSU. Do others agree? If not, then what else might it
    >> be?
    >>
    >>
    >> Reply-to address is real
    >> -- John

    >
    >One question would be about the surge itself. Were other devices in the
    >house affected ? Was the surge protector damaged ? Some surge protectors
    >have a status LED that lights up when the surge protector itself is fried.
    >(Of several I own, one has the LED.)
    >
    >Naturally, the power supply is the first thing to feel the effects of the
    >surge. And with the limited feedback range on the control loop, it's also
    >possible the overvoltage could be transferred through to the outputs.
    >(The transformer within the power supply likely has a breakdown rating
    >of more than 1100 volts, and lightning could easily jump across there
    >and go right into the DC outputs. The sticker on the ATX supply that
    >says "hi pot tested", verifies that the transformer can take at
    >least 1100 volts across the insulation inside it. That is intended to
    >stop certain kinds of power company issues going straight into the PC,
    >but can't stop lighting, because nothing stops a direct lightning
    >hit.)
    >
    >Now, say the primary rails 3.3V, 5V, 12V are out of spec. The power supply
    >itself has a signal Power_Good on the main cable, which is supposed to
    >detect when the voltages are close to the final values, at start up. The
    >motherboard won't start running unless there is Power_Good asserted by
    >the power supply. The motherboard stays in reset, until Power_Good is
    >asserted. If the rails were substantially low, then the computer would
    >sit there with a black screen, fans running.
    >
    >To have your current symptoms then, you'd need a rail to drop to a low
    >voltage, Power_Good to remain asserted, and other circuits on the motherboard
    >to still "feed good enough" for the computer itself not to crash. Which
    >seems a bit strange.
    >
    >I think there is more to it than power supply, but swapping in another
    >supply for a test would be a good thing to try. If someone has a
    >multimeter handy, they can take the side off the PC, clip the black
    >ground lead to a screw on the I/O plate on the back of the computer,
    >then take the red lead, and probe the exposed metal within each hole
    >of the nylon shell of the main connector. In rough round numbers, the
    >primary rails should be within 5% tolerance. So if you probed where the
    >yellow wire went into the nylon shell of the PSU connector, the meter
    >would read 12.00 on the 20V range when you touched the metal inside where
    >the yellow wire meets the motherboard. A 5% tolerance, means any value
    >between 11.4V and 12.6V is acceptable.
    >
    >Power supply specs, oldest to newest... Pinout tables...
    >
    >http://web.archive.org/web/20030424...org/developer/specs/atx/ATX_ATX12V_PS_1_1.pdf (page 27)
    >
    >http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf (page 30)
    >
    >http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf (page 37)
    >
    >The rails used for Internet and USB, could be different as well. USB
    >at the interface pads, may be using the +5VSB rail. And if that was
    >out of spec enough, the PC would shut off because there isn't enough
    >voltage to run supervision logic. The Internet would rely on several voltages,
    >such as 3.3V or an onboard regulator that converts 3.3V into an even
    >lower voltage for the core logic of the LAN chip. (Many LAN chips use
    >two rails, one rail being internal on the motherboard.) And I really have
    >to wonder why the PC is still running, if multiple rails are out of
    >whack. You'd think something would crash or shut down.
    >
    >Another question you'd have to ask, is whether the hard drive(s) were
    >damaged. The hard drive has surge protection devices on +5V and +12V.
    >A sustained overvoltage on either rail, causes the surge protector
    >device on the drive to get burned. Such a situation may arise on a
    >computer with a 250W Bestec brand supply, and a failure there
    >comes from the supply output rising on its own, to a higher than
    >normal value.
    >
    >I'm not liking the symptoms here, because I don't have a good explanation
    >for them. You can try another supply, especially if you don't have
    >a multimeter. Swapping is easy to do, even for a novice, as long as
    >they take pictures with a digital camera and put everything back the
    >way they found it. If you aren't there personally to help, you can
    >use pictures from this web page, to aid in discussions about
    >connectors (such as "why are these Molex 1x4 connectors on the
    >hard drives, so hard to remove" :) ). When removing the Molex 1x4
    >from a drive, you should use your fingers, as attempting to apply
    >tools to it, the tools slip off. Wiggling it is what I attempt
    >to do. Modern supplies have a compression section on either
    >side of the Molex, which when compressed, pushes against the
    >drive and eases the connector out. But the older connectors
    >don't have that feature, and it takes a fair bit of finger
    >strength to get them to budge.
    >
    >http://www.playtool.com/pages/psuconnectors/connectors.html
    >
    >(Hard on the fingers...)
    >http://www.playtool.com/pages/psuconnectors/peripheralpic.jpg
    >
    >Good luck, and post back if the symptoms aren't resolved. I
    >feed there is more at work here than just supply. Maybe a
    >USB device is damaged and overloading something ? With all
    >excess USB devices disconnected, does the LAN still run ?
    >
    > Paul



    Thanks, Paul, for the extensive and detailed reply. I've passed it
    along to my daughter (a techie who's as capable of understanding it as
    I am).

    Yes, there were other devices in the house that were damaged -- a
    wired smoke alarm and the controller board for the furnace and (she
    thinks) the router. Another computer in the house is also misbehaving
    but they haven't gotten into that one yet.

    The latest word is that she got the usb working by deleting the ports
    and letting them be re-discovered and reinstalled. The network is
    flakey -- works most of the time but not always. She's wondering if
    the router was damaged; she's on a wired port and sees the flakiness,
    but a laptop using a wireless connection seems to work fine. (I don't
    know whether the laptop was plugged in when the surge hit.)

    From the sound of it, the drives are okay and the computer never
    showed any damage except forthe usb and enet misbehavior. So it's
    starting to look like the computer -- with its mobo replaced -- may be
    okay after all. (Her big fear was that the real problem was somewhere
    besides the board -- e.g., the psu -- and that she had fried the
    second board by connecting it. That appears not to be the case.)



    -- john
    Reply-to address is real
     
    john, May 16, 2011
    #3
  4. John

    geoff Guest

    Is the internet cable?

    --g
     
    geoff, May 17, 2011
    #4
  5. John

    john Guest

    On Tue, 17 May 2011 10:34:34 -0400, "geoff" <> wrote:

    >Is the internet cable?
    >
    >--g
    >

    Yes, cable internet.

    -- john
    Reply-to address is real
     
    john, May 18, 2011
    #5
  6. John

    geoff Guest

    I also had a lightning strike near the house. It took out the garage door
    opener, garbage disposal, and the dryer. The flexible tubing that fed gas
    to the hot water heater broke open with flames shooting out.

    Everything was fixed but about every two or three weeks I had to reboot the
    router (new) because the connection was lost. When I switched to digital
    phone, the cable guy said the connectors were black as pitch. He changed
    the cable going from the house to the road and that seem to fix the
    connection issue.

    --g
     
    geoff, May 18, 2011
    #6
  7. John

    westom Guest

    On May 15, 9:09 pm, john <> wrote:
    > (Her big fear was that the real problem was somewhere
    > besides the board -- e.g., the psu -- and that she had fried the
    > second board by connecting it. That appears not to be the case.)


    Paul's suggestion of using the multimeter would accuse or exonerate
    the power supply in but a minute - no more doubts. IOW take
    measurements of key voltages. If the three digit numbers are good,
    then move on to other suspects.

    Appears she had a surge on AC mains. This due to no properly earthed
    'whole house' protector. So the surge was inside hunting
    destructively for earth ground. Normally protection inside he PSU
    makes these surges irrelevant. But an adjacent protector can connect
    that surge directly to the motherboard. Bypass protection inside the
    supply.

    Well, surge incoming to the motherboard. Apparently outgoing via
    the USB port and router. To have damage, everything must have both an
    incoming and outgoing path. The surge can pass through everything
    from cloud to earth. But only some items in that path to earth get
    damaged.

    She needs some means of testing the interconnection between USB and
    router. The router has an address typically of 192.168.0.1 or
    192.168.1.1. So using Command Prompt window, enter the command
    "PING -t 192.168.x.1" without quotes and with x replaced by 0 or 1.
    (To better learn that IP address, enter "IPCONFIG /ALL" in the Command
    Prompt window.)

    That ping should occur constantly and with response times of less
    than 20 milliseconds. If yes, then the interconnection is good. Move
    on to other suspects.

    Well, the surge then may have gone from router to earth via the phone
    or cable line. So "PING -t xxxx" where xxxx is some internet
    site. Again, that Ping must be constant without interruptions (but
    will be a longer response time). If good, then move on to other
    suspects.

    These tests (even from the power supply) provide numbers. Post
    those numbers here to learn of more information embedded in those
    numbers.
     
    westom, May 18, 2011
    #7
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