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No Power!

Discussion in 'PC Hardware' started by steve d. podleski, Nov 15, 2006.

  1. While I was working on my pc, the system shut down as if the power failed.
    I tried to turn the system back on but nothing happened. The only sign of
    power was a green light on the motherboard. I replaced the power supply with
    a used Dell power supply that I got at a surplus store; this used power
    supply had an extra bundle of blue and while cable with a small connector
    that, I guess, needs to be connected to the motherboard but I could not find
    a compabatible socket; the old power supply had only one connector to the
    motherboard.This replacement power supply had no effect including not
    lighting the green light on the motherboard.

    Also, when the computer was functional, I would get occasional warnings
    from the BIOS that the fan had 0 rpms but the after a few seconds, the fan
    rpm was back to full value; I did not see this warning before the compuer
    shut down.

    This system is over 5 years old with a 1.1GHz Athlon, ASUS motherboard and
    300W power supply and 768MB Crucials (sp?) RAM.

    Any ideas?
     
    steve d. podleski, Nov 15, 2006
    #1
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  2. steve d. podleski

    Arno Wagner Guest

    In comp.sys.ibm.pc.hardware.misc steve d. podleski <> wrote:
    > While I was working on my pc, the system shut down as if the power failed.
    > I tried to turn the system back on but nothing happened. The only sign of
    > power was a green light on the motherboard. I replaced the power supply with
    > a used Dell power supply that I got at a surplus store; this used power
    > supply had an extra bundle of blue and while cable with a small connector
    > that, I guess, needs to be connected to the motherboard but I could not find
    > a compabatible socket; the old power supply had only one connector to the
    > motherboard.This replacement power supply had no effect including not
    > lighting the green light on the motherboard.


    Bad idea to try a custom PSU. In the worst case you could completely
    fry your system, because they might use a different connector layout.
    As with the extra wires: How do you know they are not the +12v 50A
    extra power line? If connected to a power-putton input, what you
    hear will be the "pop" when the chipset explodes....

    > Also, when the computer was functional, I would get occasional warnings
    > from the BIOS that the fan had 0 rpms but the after a few seconds, the fan
    > rpm was back to full value; I did not see this warning before the compuer
    > shut down.


    Typical for a fan with bearing trouble.

    > This system is over 5 years old with a 1.1GHz Athlon, ASUS motherboard and
    > 300W power supply and 768MB Crucials (sp?) RAM.


    Get a known-to be good PSU and try that. Check all fans. If the
    CPU fan stopped, the CPU may be fried.

    Arno
     
    Arno Wagner, Nov 15, 2006
    #2
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  3. Arno.

    Thanks for helping.

    How can I tell if the PSU fan is bad without having the PSU installed?

    "Arno Wagner" <> wrote in message
    news:...
    > In comp.sys.ibm.pc.hardware.misc steve d. podleski
    > <> wrote:
    >> While I was working on my pc, the system shut down as if the power
    >> failed.
    >> I tried to turn the system back on but nothing happened. The only sign
    >> of
    >> power was a green light on the motherboard. I replaced the power supply
    >> with
    >> a used Dell power supply that I got at a surplus store; this used power
    >> supply had an extra bundle of blue and while cable with a small connector
    >> that, I guess, needs to be connected to the motherboard but I could not
    >> find
    >> a compabatible socket; the old power supply had only one connector to the
    >> motherboard.This replacement power supply had no effect including not
    >> lighting the green light on the motherboard.

    >
    > Bad idea to try a custom PSU. In the worst case you could completely
    > fry your system, because they might use a different connector layout.
    > As with the extra wires: How do you know they are not the +12v 50A
    > extra power line? If connected to a power-putton input, what you
    > hear will be the "pop" when the chipset explodes....
    >
    >> Also, when the computer was functional, I would get occasional warnings
    >> from the BIOS that the fan had 0 rpms but the after a few seconds, the
    >> fan
    >> rpm was back to full value; I did not see this warning before the compuer
    >> shut down.

    >
    > Typical for a fan with bearing trouble.
    >
    >> This system is over 5 years old with a 1.1GHz Athlon, ASUS motherboard
    >> and
    >> 300W power supply and 768MB Crucials (sp?) RAM.

    >
    > Get a known-to be good PSU and try that. Check all fans. If the
    > CPU fan stopped, the CPU may be fried.
    >
    > Arno
    >
    >
     
    steve d. podleski, Nov 15, 2006
    #3
  4. steve d. podleski

    Arno Wagner Guest

    In comp.sys.ibm.pc.hardware.misc steve d. podleski <> wrote:
    > Arno.


    > Thanks for helping.


    > How can I tell if the PSU fan is bad without having the PSU installed?


    Actually I meant the CPU fan. Or do you monitor the PSU fan as well?
    It would require a special fan-like cable from the PSU to the maniboard.

    If you really want to test the PSU fan. easiest is to switch it
    on. For that you need to connect the -pwr line and GND. A guide
    with photos is here:
    http://www.rojakpot.com/showarticle.aspx?artno=268&pgno=0
    If the fan does not spin after this, it is broken.

    Arno

    > "Arno Wagner" <> wrote in message
    > news:...
    >> In comp.sys.ibm.pc.hardware.misc steve d. podleski
    >> <> wrote:
    >>> While I was working on my pc, the system shut down as if the power
    >>> failed.
    >>> I tried to turn the system back on but nothing happened. The only sign
    >>> of
    >>> power was a green light on the motherboard. I replaced the power supply
    >>> with
    >>> a used Dell power supply that I got at a surplus store; this used power
    >>> supply had an extra bundle of blue and while cable with a small connector
    >>> that, I guess, needs to be connected to the motherboard but I could not
    >>> find
    >>> a compabatible socket; the old power supply had only one connector to the
    >>> motherboard.This replacement power supply had no effect including not
    >>> lighting the green light on the motherboard.

    >>
    >> Bad idea to try a custom PSU. In the worst case you could completely
    >> fry your system, because they might use a different connector layout.
    >> As with the extra wires: How do you know they are not the +12v 50A
    >> extra power line? If connected to a power-putton input, what you
    >> hear will be the "pop" when the chipset explodes....
    >>
    >>> Also, when the computer was functional, I would get occasional warnings
    >>> from the BIOS that the fan had 0 rpms but the after a few seconds, the
    >>> fan
    >>> rpm was back to full value; I did not see this warning before the compuer
    >>> shut down.

    >>
    >> Typical for a fan with bearing trouble.
    >>
    >>> This system is over 5 years old with a 1.1GHz Athlon, ASUS motherboard
    >>> and
    >>> 300W power supply and 768MB Crucials (sp?) RAM.

    >>
    >> Get a known-to be good PSU and try that. Check all fans. If the
    >> CPU fan stopped, the CPU may be fried.
    >>
    >> Arno
    >>
    >>
     
    Arno Wagner, Nov 15, 2006
    #4
  5. steve d. podleski

    Paul Guest

    steve d. podleski wrote:
    > Arno.
    >
    > Thanks for helping.
    >
    > How can I tell if the PSU fan is bad without having the PSU installed?
    >


    The fan monitor has a "minimum RPM" value. When the RPMs
    drop below the minimum value, the readout goes to zero.

    I have a motherboard, where the minimum measurable value is
    1800RPM. If the fan spins at 1801 RPM, the readout says 1801.
    If the fan spins at 1799, the readout says 0. Your minimum
    could be different than this.

    This problem is caused by a counter overflow in the monitor chip.
    There is a divider in the monitor chip, that can be adjusted, so
    that lower fan RPM values can be read. A program like Speedfan
    from almico.com may be able to make the lower fan values readable.
    (At least, up to the limits of the adjustment in the monitor chip.)

    The motherboard BIOS seems to be ill equipped to set this up
    properly. The motherboard BIOS can set the threshold quite high.
    Speedfan uses an autoranging algorithm, where the monitor chip
    is adjusted down, until a value can be seen. If the fan *is*
    actually zero, this can still be detected. When the monitor
    is dialled as low as possible, it can still properly read out
    a zero RPM fan as being zero.

    A PSU can be tested, by connecting PS_ON# to COM. It is best to
    have a small amount of load on the PSU, so that it can regulate
    properly. An old disk drive, for example, draws 5V @ 1A and 12V @ 0.5A
    and is better than nothing, as a dummy load. When PS_ON# is connected
    to an adjacent COM pin, the fan will start to spin. If the fan
    doesn't spin, you'd need a multimeter to figure out what is working
    or not working. (The supervisor voltage on the PSU, is called +5VSB.
    The power supply cannot run the rest of the outputs, unless the +5VSB
    is operating first. If the +5VSB fails or is overloaded, there is
    no chance of the other voltages being generated.)

    Watch it with the old Dell supplies! They can fry an ordinary computer.
    Especially if they have that "extra" connector. Look for Dell pinouts
    on the web for more details, before using one.

    Paul
     
    Paul, Nov 15, 2006
    #5
  6. steve d. podleski

    Guest

    steve d. podleski wrote:
    > While I was working on my pc, the system shut down as if the power failed.
    > I tried to turn the system back on but nothing happened. The only sign of
    > power was a green light on the motherboard. I replaced the power supply with
    > a used Dell power supply that I got at a surplus store; this used power
    > supply had an extra bundle of blue and while cable with a small connector
    > that, I guess, needs to be connected to the motherboard but I could not find
    > a compabatible socket; the old power supply had only one connector to the
    > motherboard.This replacement power supply had no effect including not
    > lighting the green light on the motherboard.
    >


    Don't connect that if if your computer is not a Pentium 2 or Pentium 3
    Dell! Not the same one. Wires are very different different.

    If you're lucky, you can get the correct power supply for your
    computer, and the motherboard will still work.



    > Also, when the computer was functional, I would get occasional warnings
    > from the BIOS that the fan had 0 rpms but the after a few seconds, the fan
    > rpm was back to full value; I did not see this warning before the compuer
    > shut down.
    >
    > This system is over 5 years old with a 1.1GHz Athlon, ASUS motherboard and
    > 300W power supply and 768MB Crucials (sp?) RAM.
    >
    > Any ideas?



    Get a standard ATX PSU, and try again.
     
    , Nov 16, 2006
    #6
  7. steve d. podleski

    kony Guest

    On Wed, 15 Nov 2006 16:26:35 GMT, "steve d. podleski"
    <> wrote:

    >While I was working on my pc, the system shut down as if the power failed.


    You were working on it while it was turned on ??!!

    Could you describe what you "think" might have happened?
    I suspect you might have shorted something, tripping the PSU
    to shut off. That might mean you needed to unplug it from
    the AC for a few minutes then retry it. If you didn't
    unplug it from AC, it might not start.


    >I tried to turn the system back on but nothing happened. The only sign of
    >power was a green light on the motherboard. I replaced the power supply with
    >a used Dell power supply that I got at a surplus store; this used power
    >supply had an extra bundle of blue and while cable with a small connector
    >that, I guess, needs to be connected to the motherboard but I could not find
    >a compabatible socket;


    What did that extra connector look like? I'd guess it's for
    the PSU fan RPM sensor- and you don't need it, shouldn't
    hook it up.

    More important, does this Dell PSU's wiring colors and pin
    positions match up to your other PSU? it might be a
    proprietary, incompatible pinout.


    >the old power supply had only one connector to the
    >motherboard.This replacement power supply had no effect including not
    >lighting the green light on the motherboard.
    >
    > Also, when the computer was functional, I would get occasional warnings
    >from the BIOS that the fan had 0 rpms but the after a few seconds, the fan
    >rpm was back to full value; I did not see this warning before the compuer
    >shut down.


    It could mean the fan was bad, or it could just mean the fan
    was running at a low RPM, low enough that the motherboard
    bios couldn't detect it's RPM properly- that's a common bios
    bug that is "Sometimes" corrected on later bios.

    I'd plug the old PSU back into the system, try to start the
    system and note whether it's fan is spinning (look at it,
    not by the bios health monitor screen). If the fan isn't
    spinning then turn the system off and decide whether to
    attempt replacing the fan (if the PSU hadn't baked for too
    long) or replacing whole PSU.


    >This system is over 5 years old with a 1.1GHz Athlon, ASUS motherboard and
    >300W power supply and 768MB Crucials (sp?) RAM.



    Depends on exactly what happened when you were working on
    it. if you think you damanged some particular part, pull
    that part out. you might also unplug AC and clear CMOS,
    then retry it.
     
    kony, Nov 16, 2006
    #7
  8. "kony" <> wrote
    "steve d. podleski"> <> wrote:
    >
    >>While I was working on my pc, the system shut down as if the power failed.

    >
    > You were working on it while it was turned on ??!!
    >
    > Could you describe what you "think" might have happened?
    > I suspect you might have shorted something, tripping the PSU
    > to shut off. That might mean you needed to unplug it from
    > the AC for a few minutes then retry it. If you didn't
    > unplug it from AC, it might not start.


    I think that I was typing when it shut off.

    I unplugged the power cord and tried starting it without success.


    >>I tried to turn the system back on but nothing happened. The only sign of
    >>power was a green light on the motherboard. I replaced the power supply
    >>with
    >>a used Dell power supply that I got at a surplus store; this used power
    >>supply had an extra bundle of blue and while cable with a small connector
    >>that, I guess, needs to be connected to the motherboard but I could not
    >>find
    >>a compabatible socket;

    >
    > What did that extra connector look like? I'd guess it's for
    > the PSU fan RPM sensor- and you don't need it, shouldn't
    > hook it up.


    I need to look at it again.

    > More important, does this Dell PSU's wiring colors and pin
    > positions match up to your other PSU? it might be a
    > proprietary, incompatible pinout.


    The Dell power supply had different colored wiring.

    >>the old power supply had only one connector to the
    >>motherboard.This replacement power supply had no effect including not
    >>lighting the green light on the motherboard.
    >>
    >> Also, when the computer was functional, I would get occasional warnings
    >>from the BIOS that the fan had 0 rpms but the after a few seconds, the fan
    >>rpm was back to full value; I did not see this warning before the compuer
    >>shut down.

    >
    > It could mean the fan was bad, or it could just mean the fan
    > was running at a low RPM, low enough that the motherboard
    > bios couldn't detect it's RPM properly- that's a common bios
    > bug that is "Sometimes" corrected on later bios.
    >
    > I'd plug the old PSU back into the system, try to start the
    > system and note whether it's fan is spinning (look at it,
    > not by the bios health monitor screen). If the fan isn't
    > spinning then turn the system off and decide whether to
    > attempt replacing the fan (if the PSU hadn't baked for too
    > long) or replacing whole PSU.


    I plugged the old PSU into the motherboard and did not connect anything
    else. The fan did not run.
    Will buy a new PSU.

    >>This system is over 5 years old with a 1.1GHz Athlon, ASUS motherboard and
    >>300W power supply and 768MB Crucials (sp?) RAM.



    > Depends on exactly what happened when you were working on
    > it. if you think you damanged some particular part, pull
    > that part out. you might also unplug AC and clear CMOS,
    > then retry it.


    How do you clear the CMOS?
     
    steve d. podleski, Nov 16, 2006
    #8
  9. steve d. podleski

    kony Guest

    On Thu, 16 Nov 2006 20:08:24 GMT, "steve d. podleski"
    <> wrote:

    >"kony" <> wrote
    > "steve d. podleski"> <> wrote:
    >>
    >>>While I was working on my pc, the system shut down as if the power failed.

    >>
    >> You were working on it while it was turned on ??!!
    >>
    >> Could you describe what you "think" might have happened?
    >> I suspect you might have shorted something, tripping the PSU
    >> to shut off. That might mean you needed to unplug it from
    >> the AC for a few minutes then retry it. If you didn't
    >> unplug it from AC, it might not start.

    >
    >I think that I was typing when it shut off.


    Oh, by working I'd thought you meant handling the hardware,
    case open, etc.



    >> More important, does this Dell PSU's wiring colors and pin
    >> positions match up to your other PSU? it might be a
    >> proprietary, incompatible pinout.

    >
    >The Dell power supply had different colored wiring.



    Sometimes an OEM will substitute a different color, for
    example blue for yellow (on the 12V leads), but it is
    consistent, if one notes all the places these might've been
    substituted, the pin positions remain the same as standard
    ATX. Dell definitely did use some proprietarily wired PSU
    though, it's quite possible that's what you have.


    >>you might also unplug AC and clear CMOS,
    >> then retry it.

    >
    >How do you clear the CMOS?


    Unplug AC from PSU and either pull the battery for a few
    minutes or use the clear CMOS jumper- either labeled on the
    board or consult the manual for it's location.
     
    kony, Nov 17, 2006
    #9
  10. steve d. podleski

    Guest

    kony wrote:
    > On Thu, 16 Nov 2006 20:08:24 GMT, "steve d. podleski"
    > <> wrote:
    >
    > >"kony" <> wrote
    > > "steve d. podleski"> <> wrote:
    > >>
    > >>>While I was working on my pc, the system shut down as if the power failed.
    > >>
    > >> You were working on it while it was turned on ??!!
    > >>
    > >> Could you describe what you "think" might have happened?
    > >> I suspect you might have shorted something, tripping the PSU
    > >> to shut off. That might mean you needed to unplug it from
    > >> the AC for a few minutes then retry it. If you didn't
    > >> unplug it from AC, it might not start.

    > >
    > >I think that I was typing when it shut off.

    >
    > Oh, by working I'd thought you meant handling the hardware,
    > case open, etc.
    >
    >
    >
    > >> More important, does this Dell PSU's wiring colors and pin
    > >> positions match up to your other PSU? it might be a
    > >> proprietary, incompatible pinout.

    > >
    > >The Dell power supply had different colored wiring.

    >
    >
    > Sometimes an OEM will substitute a different color, for
    > example blue for yellow (on the 12V leads), but it is
    > consistent, if one notes all the places these might've been
    > substituted, the pin positions remain the same as standard
    > ATX. Dell definitely did use some proprietarily wired PSU
    > though, it's quite possible that's what you have.
    >


    If the dell PSU has the 6 wire plug, with 3 blue, and 3 black or
    white,. it's definitely the wrong PSU.


    >
    > >>you might also unplug AC and clear CMOS,
    > >> then retry it.

    > >
    > >How do you clear the CMOS?

    >
    > Unplug AC from PSU and either pull the battery for a few
    > minutes or use the clear CMOS jumper- either labeled on the
    > board or consult the manual for it's location.
     
    , Nov 18, 2006
    #10
  11. Bought a new PSU and voila, system powers up and boots.

    Lucky to not have damaged the motherboard with my blunderings with the
    surplus Dell PSU.

    Thanks to all for their help!

    "steve d. podleski" <> wrote in message
    news:...
    > While I was working on my pc, the system shut down as if the power failed.
    > I tried to turn the system back on but nothing happened. The only sign of
    > power was a green light on the motherboard. I replaced the power supply

    with
    > a used Dell power supply that I got at a surplus store; this used power
    > supply had an extra bundle of blue and while cable with a small connector
    > that, I guess, needs to be connected to the motherboard but I could not

    find
    > a compabatible socket; the old power supply had only one connector to the
    > motherboard.This replacement power supply had no effect including not
    > lighting the green light on the motherboard.
    >
    > Also, when the computer was functional, I would get occasional warnings
    > from the BIOS that the fan had 0 rpms but the after a few seconds, the fan
    > rpm was back to full value; I did not see this warning before the compuer
    > shut down.
    >
    > This system is over 5 years old with a 1.1GHz Athlon, ASUS motherboard and
    > 300W power supply and 768MB Crucials (sp?) RAM.
    >
    > Any ideas?
    >
    >
     
    steve podleski, Nov 18, 2006
    #11
  12. steve d. podleski

    Arno Wagner Guest

    In comp.sys.ibm.pc.hardware.misc steve podleski <> wrote:
    > Bought a new PSU and voila, system powers up and boots.


    Congratulations.

    > Lucky to not have damaged the motherboard with my blunderings with the
    > surplus Dell PSU.


    Indeed. Custom hardware sometimes is an accident waiting to happen...

    Arno

    > Thanks to all for their help!


    > "steve d. podleski" <> wrote in message
    > news:...
    >> While I was working on my pc, the system shut down as if the power failed.
    >> I tried to turn the system back on but nothing happened. The only sign of
    >> power was a green light on the motherboard. I replaced the power supply

    > with
    >> a used Dell power supply that I got at a surplus store; this used power
    >> supply had an extra bundle of blue and while cable with a small connector
    >> that, I guess, needs to be connected to the motherboard but I could not

    > find
    >> a compabatible socket; the old power supply had only one connector to the
    >> motherboard.This replacement power supply had no effect including not
    >> lighting the green light on the motherboard.
    >>
    >> Also, when the computer was functional, I would get occasional warnings
    >> from the BIOS that the fan had 0 rpms but the after a few seconds, the fan
    >> rpm was back to full value; I did not see this warning before the compuer
    >> shut down.
    >>
    >> This system is over 5 years old with a 1.1GHz Athlon, ASUS motherboard and
    >> 300W power supply and 768MB Crucials (sp?) RAM.
    >>
    >> Any ideas?
    >>
    >>
     
    Arno Wagner, Nov 18, 2006
    #12
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