Computer keeps re-booting

Discussion in 'Computer Information' started by shareyourknowledge, Mar 10, 2008.

  1. Lately, my computer has been running slow, but this morning the
    computer wouldn't go to Windows. It just kept re-booting. I read
    overheating can be one problem so I checked inside and it is fairly
    dust-free. The fan is working, although it makes a high-pitched noise.
    The cpu temp. runs about 104 degrees. I don't know if this is too high
    or if it's a normal temp.I noticed a lithium battery on the
    motherboard. I think it runs the clock but i wasn't sure if a bad
    battery can also co tribute to a slow or overheated computer.Any
    suggestion on what to check?
    shareyourknowledge, Mar 10, 2008
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  2. shareyourknowledge

    Baron Guest

    Start looking for malware, virus etc.
    Baron, Mar 10, 2008
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  3. I've tried to do that by using safe mode, Windows still won't come up.
    Can i check it in the CMOS setup utility window? I just checked in
    the advanced BIOS features and anti-virus protection is enabled.
    shareyourknowledge, Mar 10, 2008
  4. I just noticed what looks like another fan. It's called a sleeve
    bearing, but it's not operating. Could this be causing overheating?
    shareyourknowledge, Mar 11, 2008
  5. shareyourknowledge

    Paul Guest

    So far, you haven't identified the brand and model number of the
    computer, or whether it is a home built machine. Or the OS you are

    If we knew what machine, or could find pictures, it would make it
    easier to answer.

    If the fan is on the chipset heatsink, it would depend on the era
    of machine, as to how important it is. On old machines, the chipset
    dissipates maybe 2W. The fan is not quite as critical there. Some
    of the newer machines, have 20W power dissipation, and the fan
    must be running if you expect stability.

    The units of temperature are important. If it was "104 C" , then
    the chip would be overheating. If it was "104 F", that is barely
    above human body temperature, and not a problem.

    The TCAV setting in the BIOS, is of limited usage. For malware
    protection, you want to add software to your Windows install. 1/P2B_series/P2B/index.htm

    "...also include an anti boot-virus (TCAV ; TREND Chip Away Virus)
    BIOS which can protect your system from being infected by boot-type
    viruses during startup."

    Some antivirus companies, provide a download of their product which
    will operate for an evaluation period (30 days). If you have a
    malware problem, you can use the evaluation period to clean
    the machine of the virus. I did that using Kaspersky, and
    when the trial period was up, I bought a copy at Best Buy.
    It is a fairly annoying product, so you always know it is

    Since Windows is not coming up, it may be difficult to install it :-(

    The CMOS coin cell will not make a slow or overheating computer.
    on some computers, if the battery is below about 2.4V, the
    computer may not POST properly. In that case, you may not see the
    drive light flashing at all. But if there is some attempt to boot,
    and some number of files are loading, before it croaks, then the
    battery is probably not involved.

    I can see a couple possibilities besides malware.

    You could have bad electrolytic capacitors on the motherboard.
    These affect the stability of the CPU, and the computer might
    crash. The second hardware possibility, is a problem with the
    power supply. On some machines, just as the desktop is about to
    appear, the extra load on the power supply "tips the machine over",
    and causes a restart.

    To check for bad caps, you're looking for stuff like this.
    These are on the motherboard, and probably near the CPU.
    There may also be a brown stain on the PCB, near the base
    of the capacitor - that would be escaped electrolyte, a liquid
    which eventually dries and leaves a stain.

    Paul, Mar 11, 2008
  6. This is my sons computer he bought at PC Club. I don't know if this is
    a model but it says AMD Athion. The chip has the letters MSI. The
    computer must be at least five years old if not older. I'll follow
    your advice and see what i can do. Many thanks.
    shareyourknowledge, Mar 11, 2008
  7. shareyourknowledge

    Paul Guest

    I knew I forgot something. The second possibility, is the power supply.
    In terms of computer failures, they are probably number one. Hard
    drives are pretty frequent, but a bit easier to guess at, as the
    source of a problem. Motherboard cap failures cover a period of
    several years, where bad batches of electrolytic capacitors
    were manufactured. Some motherboard brands are worse than others
    (one, in fact, resulted in a successful class action suit).

    For the motherboard, you can try a visual inspection.

    For a power supply, a multimeter can be used to measure the
    voltages, or alternately, and just as valid, is swapping
    another supply in place. Not every power supply problem lends
    itself to detection with the multimeter. (Like a problem which
    is intermittent, a bad connection that lasts a fraction
    of a second.) I have one spare I keep here, for such
    emergencies. Not a very good supply, but good enough for a
    2 minute test.

    Paul, Mar 11, 2008
  8. shareyourknowledge

    tony sayer Guest

    You could have bad electrolytic capacitors on the motherboard.
    Thats the most likely problem have had that happen with a lot of
    machines and the real answer is a new MB but that may well require a new
    processor etc. The caps can be replaced but is a piggy of a job to do!..

    Also you could try another power supply these are a number one suspect
    for this sort of problem..
    tony sayer, Mar 11, 2008
  9. Good info again. Thanks. I have a question on the power supply. I'm
    assuming the fan inside the power supply is independent of the power
    supply itself, because the fan runs. But the power supply can still be
    bad? Just trying to educate myself.
    shareyourknowledge, Mar 11, 2008
  10. shareyourknowledge

    HLS Guest

    I just noticed what looks like another fan. It's called a sleeve
    bearing, but it's not operating. Could this be causing overheating?

    I am not sure exactly what you are talking about, but if that fan on
    top of your processor chip is not functioning, it can easily result in
    overheating and reboot failure. A new one is maybe ten bucks and
    a little heat transfer compound.

    The main power supply can be experiencing failures even if the
    fan is running, and this is a common cause of problems in aging

    HLS, Mar 11, 2008
  11. shareyourknowledge

    dullpain Guest

    The most common causes of rebooting:
    Overheating: if your CPU fan is spinning, has not come loose off the
    processor, and the side of the case is open your machine is not overheating.
    More likely:
    Dying hard drive or power supply, most likely the latter.
    Dying hard drives tend to cause random BSODs as they fail if it is your C
    drive. It would behoove you, if you can connect the hard drive to another
    computer, to back up your files before you doing anything else.
    dullpain, Mar 11, 2008
  12. shareyourknowledge

    Paul Guest

    The fan is usually powered from some source of +12V. If you heard the
    fan, it might mean that +12V worked. But you wouldn't know about the
    others. Since control of the supply is tied to +5VSB, you can have
    supplies that switch themselves on and off (oscillation), because
    of a problem with PS_ON# or with the +5VSB second power supply.

    By showing you the following picture, I'm not hoping to turn you into a
    circuit engineer, but this shows the basic flow of the ATX supply.
    You're right, in that the output stage is pretty simple, so it is
    unlikely the +12V would work, and the +3.3V or +5V wouldn't.
    Maybe if an output filter cap was bad, there'd be excessive ripple,
    which could upset the PC. In any case, you can have a glance at this,
    to see what they hide in the "box". This is the only schematic I've
    ever seen for one of these, and the author of this web site prepared it
    by tracing the circuit by hand.

    Paul, Mar 11, 2008
  13. shareyourknowledge

    Baron Guest

    Paul has passed on some good advice.

    If that fan is on the CPU heatsink then it needs sorting out before
    anything else.

    If the temperature you quoted was in degrees centigrade then thats very
    bad. The Athlon CPU will not last long above 90 centigrade.
    Baron, Mar 11, 2008
  14. shareyourknowledge

    Baron Guest

    Now Paul, that is just downright cruel. :)

    I used to repair the dam things! Fortunately it is now less costly to
    just bin them. That PSU design must go back 15 years or so. DTK was a
    good manufacturer to work with, knowledgeable engineers that bent over
    backwards to help you when you needed it.

    Are they still around ?
    Baron, Mar 11, 2008
  15. The cpu fan works but it makes noise. I might try oiling it first. The
    one that doesn't work is the case fan, the one at the back. I think
    this might draw the heat out of the chassis. I'll try fixing the fans
    first before i spend more money. Hopefully it just the fans.I did see
    the up to 111 degrees about 5 minutes after i turned on the
    computer. Regards.
    shareyourknowledge, Mar 11, 2008
  16. shareyourknowledge

    HLS Guest

    Ive had this happen from a fan not functioning or cooling fins that are
    with dust bunnies.

    Hard drive problems can be an issue. I went through that with dammittohell
    Windows and the hard drive wasnt really the problem. The software
    caused the issue. Reformatting and reinstalling corrected the Bill Gates

    Microsoft is no friend of mine.
    HLS, Mar 12, 2008
  17. Here's an update. I was trying to locate the whirring sound inside the
    case.Thought it was a fan but i isolated it to one of the hard drives.
    The other one runs quiet, so i wonder if this is a symptom of a bad
    hard drive which could be causing my re-booting.? What happens now
    when the computer is re-booting is i get a one second hum (a surge
    maybe?) then a quick blue screen with text on it. It's only visible
    for a split second, then the cycle starts over. I use compressed air
    today to get rid of the dust. All fans work except the case fan. I
    haven't done any electrical testing yet. Just trying to check the easy
    stuff first. Regards.
    shareyourknowledge, Mar 13, 2008
  18. shareyourknowledge

    w_tom Guest

    Disk drives do not cause rebooting. Is a drive defective? Then
    what do system (event) logs say about the defect? What do the logs
    state about the reboot? IOW get facts long before suspecting any
    component. What does Device Manager report? What do the comprehensive
    hardware diagnostics (provided free by responsible computer
    manufacturers) report? You have no reason to suspect anything yet
    because the only facts are rebooting and a noise. Neither identifies
    any part as defective. Any conclusion from those two facts is only
    wild speculation.

    If the chassis is open, then computer should work with no chassis
    fan running and the room temperature at 100 degrees F. Trying to cure
    a reboot problem by clearing dust is simply curing symptoms. Heat is
    used to make failures harder - so that failures can be easily locate
    by diagnostics. Your computer with dust should work even when room
    temperature is 30 degrees higher. If not, then a hardware problem
    exists. Blowing out dust only 'cures symptoms' - does not solve any
    w_tom, Mar 13, 2008
  19. shareyourknowledge

    Bluesplayer Guest

    I had exactly the same problem , the cure for me was this .:

    First disconnect power supply and remove all cards ide cables and ram
    Next get the hoover and clean the board of any dust and suck out all
    slots .
    Get some isopropyl , ( square shaped medical swabs are ideal ), and
    clean all the copper contacts on each card , and also fold a swab in
    half and push it into all the slots and clean inside , including ram
    slots , everything even rub over the board just get everything very
    very clean . Hoover once more .
    Now replace everything and reboot , enter your bios and choose fail
    safe options .

    You can try booting at this stage , but i strongly recommend you to re-
    install windows, just to eliminate a corrupt registry

    This worked for me .
    Bluesplayer, Mar 15, 2008
  20. shareyourknowledge

    e.w. Guest

    If it helps, I have found faulty RAM to cause this. Also, if the CPU
    fan is not properly seated, the CPU will overheat tripping the thermal
    e.w., Mar 15, 2008
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