heat sink fan comes on for 2 seconds, stops

Discussion in 'Computer Information' started by plaidthermos, Aug 4, 2007.

  1. plaidthermos

    plaidthermos Guest

    apologies if this is not the right group to post this, please point me
    in the right direction.

    i have a computer, i'm afraid i'm not too sure of the specs. i
    believe the cpu is intel. the computer would not start at all when
    pushing the front power button. not even a click. after flipping the
    back power switch to off and back to on, the front power button would
    cause the computer to come on for a couple seconds, see a black screen
    with "windows loading" or some such on it, and then turn off. pushing
    the front power button would not do anything after that until the back
    power switch was flipped again, and then the front power button would
    give the 2 seconds on again, et cetera.

    i replaced the atx power supply, and this is what happens now:

    after plugging in the power supply and flipping the back switch to on,
    _without touching the front power button_, the computer powers up.
    with the case open, i can see that the fan on the heat sink comes on
    for about two seconds and then stops. i _believe_ i hear sounds from
    the hard drive as well. there is NO activity on the screen
    whatsoever. pushing the front power button has no effect, nor does
    holding it down. the green power light on the front lights
    continuously. the red light does not appear. the only way to get it
    out of this state is to turn the back power switch back to off.

    i removed three expansion cards (one modem, two network cards), and
    tried powering up with the same result. i have reseated the ram.

    if anyone has any advice, i would greatly appreciate it. i really
    don't know much about electronics, and not familiar with the proper
    vocabulary for much of what is inside the computer.

    thank you,
    plaidthermos, Aug 4, 2007
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  2. plaidthermos

    sandy58 Guest

    Glossary of PC terms etc.
    Codecs downloads
    PC repair forum

    Start>click My Computer>right-click on blank space on page.
    You will see your PC specs there.
    Is the heat sink clean? (no gunk between the cooling fins)
    Did you use the contact paste to "seat" your cpu?
    (Central Processing Unit under the heat sink)
    Did you check with your agent/supplier for the correct power supply?
    Repost if needed, -k
    sandy58, Aug 5, 2007
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  3. plaidthermos

    plaidthermos Guest

    you don't seem to understand. there is no beep, no screen activity of
    any kind when the power comes on, so "clicking my computer" is fairly
    useless advice.

    however, i did some research and i think i have identified many of the

    fastfame 3slap

    This slot socket 370 motherbaord uses the Intel i815EP chipset. It
    features 6 PCI,1 CNR, AGP 4x, 3 dimm slots, and AC'97. The board
    supports 66/11/133 MHz FSB, and UDMA 33/66/100. It comes with 2MB
    Flash EEPROM, Award BIOS.

    PC100 SDRAM (2 pieces)
    IBM 01K1138

    Matrox 32MB DDR AGP (256B Dual-head) video card

    i did not build this computer, so i couldn't say whether contact paste
    was used.

    the new power supply i put in is 250W, which is the same as the one i

    the computer is not any particular brand name, it appears to be either
    home- or custom-built. there is no printed documentation with it.

    plaidthermos, Aug 5, 2007
  4. plaidthermos

    plaidthermos Guest

    oh, and yes, the heat sink is full of furry dust. i have looked up
    several pages about how to remove the cpu//heat sink, but none of the
    pictures i have found seem to match what i have. i'm pretty sure it
    is a slot (not zif) socketk though. i don't see any retention clips
    on the heat sink like any i have seen on any pages though, and i can't
    figure out how to get it off.

    plaidthermos, Aug 5, 2007
  5. plaidthermos

    sandy58 Guest

    Sorry, this was advice on how to see specs.
    Seems like daft advice if you can't see ANYTHING!
    You can't even get into your bios.
    You could buy a can of compressed air comes with a long thin nozzle
    for blowing out the fins on the heat sink. Most PC outlets have them
    on sale. About the on/off switching. It's quite usual for the PC to
    restart when you have switched off using the rear power switch. When
    did the problems start? Have you had it running properly recently or
    have you just got it & from where? Why I am asking is, could you get
    any history about it? If, as you say, you are not comfortable going
    into the guts of it, your best bet is find someone who knows to have a
    look at it. If the CPU WAS overheating you would at least get a few
    minutes running from a cold start.
    You obviously have access to the 'net so check out these two links.
    sandy58, Aug 5, 2007
  6. Just a thought....and it may sound stupid but it happened to me once. I had
    an issue with my PC shutting down and/or freezing up. As it turned out my
    video card was at fault. After replacing the video card I attempted to fire
    up the PC only to have it go back off. Then it wouldn't start at all with
    the power switch....then the weirdest of things happened....the cpu and case
    fans went to cycling on and off and on and off as if possessed. After a bit
    of prodding around I found that I had somehow dislodged the main power
    connector from the mother board....just enough so that is was loosely making
    occasional light contact. My guess is that initially there was partial
    contact allowing the system to start the fans but no power to other
    necessary circuits. Then no contact therefore not power through the switch.
    Then the light contact that would power on the fans causing vibration or air
    movement to lose contact causing it to power off allowing contact again
    powering up and shutting off and so on...

    All this to say don't overlook the obvious. Check to make sure that your
    connectors to the mother board are secure. There should be a long one with
    a dozen or so pins and then possibly another square one perhaps 4 pins.
    Might just as well check the power connections to your drives while you're
    in there....and even your IDE or SATA connectors.
    The Other Doug, Aug 6, 2007
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