post 52h , 8k7a, interesting post.

Discussion in 'Epox' started by Trunk, Jan 19, 2004.

  1. Trunk

    Trunk Guest

    I have been reading/ searching quite a bit of posts on amdforums,
    apparently my problem happens for lot of people, though I wonder why now!

    my PC is in a cold room, (I live in Chicago) :), and is above the garage
    and it gets rather cold in the morning, so when I boot up the PC, it just
    beeps for couple of times while my screen is dark then boots up,
    sometimes does the memory check, then restarts and redoes it, sometimes
    it hangs just before memory check... I noticed that this only happens
    during 'cold boot' and when I press the rest button it works!

    Sometimes right when I press the power button in a cold boot, if I
    press the reset button, it works / boots fine.


    So I found this post on older Epox Posting....

    ----
    Your PSU is marginally operating within the power
    requirement of the system. When a system boots, there is this so called
    "Peak Power Load" wherein the highest power requirement of the system is
    exhibited. Usually, this happens during a cold boot. During the cold
    boot process, all systems especially the HDD and CD Drives require a lot
    of power to get started. In addition, the AGP and also the case fans
    are at their maximum power requirement state. This peak power load puts
    a lot of strain on the PSU. If the PSU is just marginally meeting the
    power requirement of the system in its normal state, during the peak
    power load it's voltage output will sag (droop) thus starving the CPU
    and probably the rams of power for a few milliseconds or maybe longer
    depending on the quality of the PSU. If the PSU output will sag long
    enough, it will trigger a safe cut off of the protective logic circuit
    in the mobo. This logic will shut off the power to the mobo components
    until the power is restored to an acceptable level. If this shut off
    stays long enough, it could actually cause the system not to boot
    properly. When you reset the system, the hdd and cd drives and fans are
    still running and will not require a peak power load which will put less
    strain on the PSU. In this case, the mobo will receive all its required
    power and boot properly. The voltage sag of the PSU during boot up
    cannot be read with a regular multi-meter since it's just a transient
    change but it can be seen with the use of an Oscilloscope if measured at
    the right point in the circuit on the mobo.

    ----

    Interesting, eh ? :)

    I had a volt-meter but did not see this transient change, I was very close
    to bring an Oscilloscope home to try it out... my PSU is from Comp USA,
    I am probably going to get another PSU and try this again...

    Trunk
     
    Trunk, Jan 19, 2004
    #1
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  2. Trunk

    John Guest

    Variations of this problem are quite common. If it occurs a bit later in the
    start cycle if can be hard disk inertia or stiction on cold mornings. The
    exact cause can vary a bit from board to board, but it is essentially
    because of a heavy current drain on switch on or parts not operating
    correctly until they reach a minimum temperature. The common fix is let it
    run for a couple of minutes then reboot. The reset button will usually do
    the job.
    John.
     
    John, Jan 19, 2004
    #2
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  3. Trunk

    Trunk Guest

    I just got my ATI card back from ATI, after putting the drivers
    my system reboots everytime after login... though when I put the
    nvidia card it is fine, I thought for long time this was a driver
    issue until I re-did my system from scratch... now I think it is
    either the PSU or Epox Mobo... I am getting a 350+ PSU
    tonight.
     
    Trunk, Jan 20, 2004
    #3
  4. Trunk

    Alec S. Guest

    Wait, wait, wait, wait, wait. I'm having some problems that sound a
    little like this (I'm not overclocking, I can't afford it). Sometimes when
    I login to Windows, the system freezes (even the mouse). If I then press
    RESET, it works. Sometimes, pressing reset does not help and I have to use
    the power button. I can't help but notice that you're talking about the
    problem being in that it's too cold. I'm in Canada, yeah, yeah, ha ha :)
    and I'm not using any heaters so it's very cold this winter: 13 degrees
    Celsius/55 Fahrenheit - indoors, I leave the fridge door open to heat the
    house :D. I've also got 6 fans (2 case fans) in my system. At first I
    thought that heat was good because electrons flow better since heat is
    really just atoms in motion. Then I learned that the colder you can get
    your system the faster and more stable you can get it. Now you're saying
    that cold is not good either? Now that I think about it, I suppose the
    problems started recently, right about the time we had the cold snap.

    So could my recent problems be due to the cold? I certainly hope so,
    because that's easy and (compared to hardware) cheap to fix (free in the
    summer). I would rather it be cold than a hardware failure. :)


    --
    Alec S.
    alec @ synetech . cjb . net


    e
     
    Alec S., Jan 20, 2004
    #4
  5. Trunk

    Trunk Guest

    I wonder if the system would freeze/shut if your CPU fans
    don't rotate at certain rpm because of the cold weather ?

    All, my ATI problem got fixed, it was the PSU, getting the
    400W fixed the problem, though I still have these cold boot
    problems, next stop: motherboard!

    Trunk
     
    Trunk, Jan 21, 2004
    #5
  6. Trunk

    John Guest

    You will find all electronic components have a max and a min temperature
    rating. Things like electrolytic capacitors become less efficient as they
    age and can cause such problems when cold.
    John
     
    John, Jan 22, 2004
    #6
  7. Trunk

    Trunk Guest

    I think I solved this problem, my capacitors on the mobo were bulged,
    I am sending the board back to Epox for repair.

    Trunk
     
    Trunk, Jan 23, 2004
    #7
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