PC power on - start, stop, start, stop, etc - eventually powers up

Discussion in 'PC Hardware' started by spodosaurus, Dec 26, 2008.

  1. spodosaurus

    spodosaurus Guest

    Hi all,

    I have a problem that has only recently started (to my knowledge) and I
    can't seem to solve it. I've got a P4 3.0GHz PC with an Asis P4P800S-X
    board, 512mb RAM, Thermaltake 430W PSU and geforece fx5200 graphics. The
    problem is that once the system is warm (and sometimes even from cold) a
    shutdown then start gets the computer spinning its fans, powering off,
    spinning fans, powering off, and repeating this cycle from 1-10+ times
    before actually POSTing. Once it POSTs, it's all fine. Sometimes the
    brief power ons result in the drives starting to power up as well, but
    usually not. I've flashed the motherboard, replaced the PSU, cleaned and
    reattached the HSF, and tried it with only CPU, GPU, RAM, and Video
    attached to the motherboard without success in solving this issue. I've
    come accross other accounts of similar issues, but they've usually been
    solved by the steps I've already taken. Any ideas on where I could go
    from here?

    TIA,

    Ari

    --
    spammage trappage: remove the underscores to reply
    Many people around the world are waiting for a marrow transplant. Please
    volunteer to be a marrow donor and literally save someone's life:
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    spodosaurus, Dec 26, 2008
    #1
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  2. spodosaurus

    Bryce Guest

    Possibly marginal available power at boot? You didn't say how many hard
    drives are connected: try with only one. Also try without the video card
    installed. Watching the power supply voltages during the boot might help.
     
    Bryce, Dec 26, 2008
    #2
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  3. spodosaurus

    spodosaurus Guest

    Doesn't even make it through post, much less all the way to boot.
    However, sometimes, like right now, it went through POST and boot and is
    working fine - if I restart it, though...
    I said above that I've tried it with the bare minimum: motherboard with
    only RAM, CPU, and video card. There's only one HDD attached when in
    use, however.
    I guess I can always give that a try. Without the graphics card it'll
    just beep.


    --
    spammage trappage: remove the underscores to reply
    Many people around the world are waiting for a marrow transplant. Please
    volunteer to be a marrow donor and literally save someone's life:
    http://www.abmdr.org.au/
    http://www.marrow.org/
     
    spodosaurus, Dec 26, 2008
    #3
  4. spodosaurus

    spodosaurus Guest

    At this point I'm guessing it has to be motherboard. The install and
    updating of ubuntu went perfectly. it still runs perfectly - when it
    actually gets to POST.

    --
    spammage trappage: remove the underscores to reply
    Many people around the world are waiting for a marrow transplant. Please
    volunteer to be a marrow donor and literally save someone's life:
    http://www.abmdr.org.au/
    http://www.marrow.org/
     
    spodosaurus, Dec 26, 2008
    #4
  5. spodosaurus

    Franc Zabkar Guest

    It may be instructive if you can determine whether it is the
    motherboard that is turning the PSU off in response to a fault
    condition, or whether it is the PSU that is turning itself off in
    response to a fault in the load. Or it may be that the motherboard is
    resetting itself for some reason without turning off the PSU. To this
    end it *might* help if you monitored the PS_ON signal (pin 14, green)
    with a multimeter. A DMM may not detect rapid transitions on this pin,
    though, even with a peak hold function.

    See http://pinouts.ru/Power/atxpower_pinout.shtml

    Does the PSU fan stop spinning, or is it only the motherboard fans
    that do this?

    Have you tried replacing your graphics card with a low power PCI card?

    - Franc Zabkar
     
    Franc Zabkar, Dec 26, 2008
    #5
  6. spodosaurus

    spodosaurus Guest

    Hi,

    Thanks for the reply.

    My voltages were all within 5% of nominal voltages on both PSUs - I
    tested these before I did anything else. I had a PSU test okay with my
    digital multimeter before, but there were fluctuations on the +5VSB line
    that were causing problems that were only detected by a PSU tester that
    was inaccurate and only reported to one decimal place, but it did update
    frequently enough that I could see the +5VSB fluctuations. Just in case
    there was a +5VSB issue, I switch the rear usb power from that line to
    +5V using the motherboard's jumpers without success.

    Ari

    --
    spammage trappage: remove the underscores to reply
    Many people around the world are waiting for a marrow transplant. Please
    volunteer to be a marrow donor and literally save someone's life:
    http://www.abmdr.org.au/
    http://www.marrow.org/
     
    spodosaurus, Dec 27, 2008
    #6
  7. spodosaurus

    spodosaurus Guest

    PSU, CPU (connected to motherboard), and case fan (connected to molex
    from PSU).
    This last suggestion got me thinking. I didn't recall this PC having
    these problems before it was given to me. I thought it was using a
    different graphics card and that I'd put the FX5200 in it (turns out the
    actual card was the original geforce mx4000 after all). I tried putting
    in a higher powered Radeon 9600 Pro card in there and turning it on from
    cold - no joy, even though it always starts when it's at room
    temperature after a few hours idle. So I popped in an old PCI card - and
    it started immediately even though it had been running.

    I'll update this if it starts having problems again in a few hours when
    I restart it after it's been running a while.

    Ari

    --
    spammage trappage: remove the underscores to reply
    Many people around the world are waiting for a marrow transplant. Please
    volunteer to be a marrow donor and literally save someone's life:
    http://www.abmdr.org.au/
    http://www.marrow.org/
     
    spodosaurus, Dec 27, 2008
    #7
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