HELP!! PC Posts (sometimes) then hangs with "static" sound...

Discussion in 'Abit' started by Ohaya, Mar 6, 2004.

  1. Ohaya

    Ohaya Guest

    Hi,

    My daughter's PC wasn't able to boot this week, and she brought it home
    this weekend for me to look at. It has an Abit KT7E motherboard, with a
    Duron 850 CPU.

    When she first told me about the problem, she said that it was making a
    sound that sounded "like static".

    Now that I have it here, I can confirm that description, and also I've
    confirmed that the sound is coming from the PC speaker.

    The machine will sometimes post, and I can get into BIOS. If I let it
    sit there in BIOS, the display eventually goes blank, and the monitor
    LED blinks yellow, indicating that it's lost video signal. When it does
    that, I start hearing the "static" sound from the PC speaker.

    Sometimes it won't post at all, just a blank screen and blinking monitor
    LED and the static sound.

    We've unplugged everything except the video card and 1 RAM stick. Still
    the same symptoms.

    We've pulled the motherboard to check for anything underneath, but found
    nothing.

    I've found this post:

    http://groups.google.com/groups?hl=...-8&selm=b6s2ta$l49$

    and I thought might be the CPU seating, so we've also pulled the CPU and
    heatsink, and reseated that and put the heatsink back on with some new
    paste. Still the same problem.

    I did notice that there's a small fan on the motherboard itself,
    probably for cooling the chipset, and sometimes doesn't turn when we
    power the machine on. If I push the fan blades, it'll start turning,
    but seems a little slow.

    When in the BIOS, I've set it to "Safe Defaults", but still the same
    thing.

    When I can get into the BIOS, the BIOS PC Health display, it shows:

    Core 1.63V
    3.3V 3.41V
    5V 4.85V
    12V 12.00V

    I'm thinking that it's either a problem with the motherboard or with the
    power supply (the slow fan?)?

    Any thoughts/suggestions on this?

    A friend is going to try to bring over a spare power supply for me to
    try this weekend, but, also, if it turns out to be the motherboard, can
    anyone recommend a reliable replacement motherboard?

    I went to a local Microcenter, and all of the motherboards they had only
    supported DDR or DDR400, whereas she has 3 sticks of 256MB PC133 SDRAM,
    so I'd like to reuse the RAM if we can.

    Apologies for the long post, and thanks in advance!!

    Jim
     
    Ohaya, Mar 6, 2004
    #1
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  2. Ohaya

    ICee Guest

    Sounds like there may be some bad caps on that older MB. Look for any
    bulging and/or discoloration on the tops and/or bottoms of the
    electrolytic capacitors on the MB.
    Any caps that look anything like this?
    http://www.careyholzman.com/caps/images/caps.jpg
     
    ICee, Mar 6, 2004
    #2
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  3. Ohaya

    Ohaya Guest


    ICee,

    I checked all the caps, and I found 3 caps that "may" be as you
    indicate: EC23, EC24, and EC27.

    I've posted a picture at:

    http://members.cox.net/ohaya/motherboard.jpg

    The 3 caps pointed to are different than your picture. They have a kind
    of beige-colored residue on top, kind of reminds me of when battery acid
    leaks from a car battery.

    The EC27 seems (hard to tell) SLIGHTLY bulged.

    The rest of the caps of the board are clean and no bulging.

    So what do you think???

    I assume that this is a multilayer board, so is it difficult to
    desolder/replace these caps?

    And again, if this board is dead, what would be a good replacement
    (needs to support AMD Duron, and hopefully have 3 SDRAM slots)? The
    KT7Es seem to be hard to find.

    Jim
     
    Ohaya, Mar 6, 2004
    #3
  4. Ohaya

    Ohaya Guest


    Hi,

    Just in case, I checked the CMOS battery, and it's measuring 2.82V. Is
    that nominal?

    Jim
     
    Ohaya, Mar 6, 2004
    #4
  5. Ohaya

    ICee Guest

    Ohaya wrote:
    Yes, those three caps are definitely bad. They are all bulging on the
    top and the beige colored residue is dried electrolyte. I see they are
    near the AGP socket; are the ones near the CPU socket all ok? The CMOS
    battery (if it's a CR2032) should be 3.3v. That is low, but would not
    cause the symptoms you have. It's there to hold any changes you make to
    the BIOS, such as date and time, and any settings other than default.
     
    ICee, Mar 6, 2004
    #5
  6. Ohaya

    ICee Guest

    ICee wrote:
    Forgot to mention that the fact that the bad caps are next to the AGP
    slot explains why you lose the display after a time.
    I'm afraid I'm not familiar with any MB that would have slots for SDRAM,
    since DDR has been out so long.
     
    ICee, Mar 6, 2004
    #6
  7. Ohaya

    Ohaya Guest


    ICee,

    Yes, all other caps, including the ones near the CPU socket, look
    "normal" (no bulging, and no residue).
     
    Ohaya, Mar 6, 2004
    #7
  8. Ohaya

    ICee Guest

    I was thinking that bad caps in the voltage regulator circuit near the
    CPU would be more likely to cause the problem, till I reread your post
    and saw that you lose the display after a time. The problem is
    definitely the bad caps near the AGP slot.
    Since a new MB with SDRAM is going to be difficult, if not impossible to
    find, you may want to try getting that MB repaired. From what I've read
    in these NG's, this place does a good job and the price is very
    reasonable:
    http://www.motherboardrepair.com/
     
    ICee, Mar 6, 2004
    #8
  9. Ohaya

    Ohaya Guest


    ICee (or anyone else),

    I was wondering... With the bad caps, would it be ok to just cut the
    caps off the board, and solder new/replacement caps to the leads that
    are left on the board?

    I have a supply of electrolytics (from "the olde days"), but I'd be a
    bit worried about desoldering something on a multi-layered board, but I
    think I could handle the above.

    Comments?

    Jim
     
    Ohaya, Mar 6, 2004
    #9
  10. Ohaya

    Ohaya Guest


    ICee,

    Hmm. My testing was with a PCI video card, not with an AGP card. Also,
    I get similar symptoms regardless of which PCI slot I install the video
    card in...
     
    Ohaya, Mar 6, 2004
    #10
  11. Ohaya

    Apollo Guest

    I'd give it a go, but consider that other caps will begin failing before
    very long, this fault is very well documented.

    Have a look here http://www.acme.com/build_a_pc/boardfinder/ to try and find
    a board compatible with the sdram. May be time for an upgrade to ddr ram or
    look on ebay for a used replacement board (bear in mind that a LOT of boards
    around the age of yours will have failing caps).

    You can pick up a new nforce2 mobo for around £25, XP2500 - £50, 512MB DDR -
    £50. One thing to remember if you change your mobo - read up on removing
    any traces of existing mobo drivers from your o/s before you shutdown for
    the change, this should enable you to change without re-install of the o/s.

    HTH
     
    Apollo, Mar 6, 2004
    #11
  12. Ohaya

    Ohaya Guest


    Ian,

    Thanks, I think that I've found a reasonable substitute, a Soyo KT7VA.
    I posted on the Soyo NG to see if anyone has any feedback on that
    motherboard, e.g., regarding the caps.

    Unfortunately, we'll have no chance to do anything with the drivers,
    since the Abit is essentially dead/won't boot, so I'm planning to
    re-install for her...
     
    Ohaya, Mar 6, 2004
    #12
  13. No, it shouldn't.
    A brand-new CR2032 measures 3.1-3.15 V, and should still be above 2.9 V
    after a few years in a board.
    2.82 V is on the edge of "the red zone", and I wouldn't expect the CMOS
    to hold data reliably. It should be replaced.
     
    Jens C. Hansen [Odense], Mar 6, 2004
    #13
  14. Ohaya

    Frank Hagan Guest

    "Thanks, I think that I've found a reasonable substitute, a Soyo KT7VA.
    I posted on the Soyo NG to see if anyone has any feedback on that
    motherboard, e.g., regarding the caps."

    If you mean a Soyo K7VTA Pro I've built a few. Very solid board, but not
    much for overclocking. It uses PC133 memory and you can't lock the PCI and
    AGP busses.

    FRH
     
    Frank Hagan, Mar 6, 2004
    #14
  15. Ohaya

    *Vanguard* Guest

    "Ohaya" said in
    How old is the Abit motherboard? Under a year? If so, the warranty
    will let you get it replaced. In fact, since Abit was one of the
    manufacturers hit with the capacitors built with the stolen but
    incomplete formula, they may replace it even if the warranty has
    expired. Doesn't hurt to ask; however, I've yet to get a response for
    any technical info question that I've submitted directly to Abit but
    maybe they are more responsive regarding warranty replacement requests
    (and they can less ignore you if you call them instead of use e-mail).

    Abit was one manufacturer, maybe the only one, to admit they got stuck
    using the defective capacitors. Also, the bulging leaky capacitors
    provide a visual clue that they are bad. Could be others are also bad
    that have opened up and dried out.

    Some articles on the leaking capacitors:
    http://www.spectrum.ieee.org/WEBONLY/resource/feb03/ncap.html
    http://www.burtonsys.com/bad_BP6/story2.html
    http://www.geek.com/news/geeknews/2003Feb/bch20030206018529.htm
     
    *Vanguard*, Mar 6, 2004
    #15
  16. Ohaya

    ICee Guest

    You're right, of course. It's a 3.0 volt battery, which will read
    slightly higher when new, as you mentioned. So used to 3.3v being used
    in the system, it just "came out" as such. :)
     
    ICee, Mar 6, 2004
    #16
  17. Ohaya

    Ohaya Guest


    Hi,

    Well, I tried submitting something through their "e-rma" website, and it
    came back and told me that the board was out of warranty and I had to
    pay $25, so, despite my misgivings, I started working on the board :).
    So far, I've been able to remove the caps (EC23, 24, and 27). They're
    all 1500 uF @ 6.2V.

    But, I only have an old solder sucker, and am having problems getting
    the solder out of the holes :(!!

    Any suggestions?

    Jim
     
    Ohaya, Mar 6, 2004
    #17
  18. Ohaya

    Ohaya Guest


    Hi,

    WHOO BOY, what a (bad) day :(...

    After all of this, I decided to bite the bullet, and we went out and got
    a new MB, an ASUS A7V8X-X and a 512MB stick of DDR333 RAM.

    Got that home, and guess what?

    Yep, the new motherboard wouldn't POST. No beeps. CPU fan not turning.

    Took the case, etc., motherboard to the store.

    After a bit of tweaking, they got the motherboard booting on their test
    bench.

    I asked them to test the motherboard with my power supply.

    Guess what?

    Yep, no boot with our power supply and the new motherboard.

    So, I bought a new power supply, and we brought the whole kit and
    kaboodle back home.

    I was curious, so I used the new power supply with the old Abit KT7E
    (the one that originally had a problem), and guess what?

    Yep, it booted fine! Mind you, this was with the 3 capacitors that were
    bulging completely removed!!

    Oh well, so it looks like I have 2 motherboards now :(, but to top it
    off, I am now having problems with trying to install Windows XP with the
    new Asus motherboard!!! I am getting a STOP error during the install,
    saying the BIOS is "not fully ACPI compliant". I've already deleted the
    original XP partition, so there's no going back to the original (now
    working) Abit KT7E :(...

    I've posted my problem on the ASUS NG, so if any of you nice folks know
    what might be going on with this, please let me know.

    Thanks for your patience!

    Jim
     
    Ohaya, Mar 7, 2004
    #18
  19. Ohaya

    *Vanguard* Guest

    "Ohaya" said in
    Try using solder wick (looks like a flat skinny strip of mesh copper).
    Dab a bit of extra solder atop the tail from the capacitor or the
    soldering pad and lay down the solder wick to absorb that solder and
    hopefully pull out the other old solder. The more layers the PCB has
    the harder it is to extract.

    Since the capacitors are bad, you could try yanking them off the board
    and just leave behind a remnant of their tails. Rather than pull away
    from the board, just twist the capacitors like you're trying to screw
    them on or off. Then the device can't absorb any heat. Be careful not
    to overheat the board. So rather than trying to desolder the capacitor,
    you destroy it by twisting it off, leaving behind the tails, and you can
    then actually solder the pad to melt the old solder and get the tail
    loose so you can use a pliers or cutter to grab the tail and pull it
    free. Then solder the hole first to lay in new solder and use the
    solder sucker to suck it all out.

    Although tempting, I probably wouldn't use higher than a 15W soldering
    iron, Make sure the tip is tinned and a apply a tiny dab of fresh
    solder on the tip to let it cover the pad you're trying to melt of the
    old solder. A little dab of extra solder that melts and lays atop the
    soldering area transfers heat a lot better than you trying to get some
    heat off the smaller surface of the end or side of the soldering iron
    tip. Also be sure you are using a non-static solder sucker. Some
    generate static. I'm assuming you've already taken other anti-static
    precautions.

    Note that just finding another capacitor of equal capacitance and
    voltage is not sufficient. You need to also match the type of the
    capacitor.
     
    *Vanguard*, Mar 7, 2004
    #19
  20. Ohaya

    Ohaya Guest


    Vanguard,

    Thanks. I saw your post too late though, as I'd already removed the
    caps :(...

    I'll now go-a-searching for replacements, but FYI, I powered the board
    on without the caps, and it booted fine!!

    Are those caps (EC23,24, and 27) only noise suppressors?

    Jim
     
    Ohaya, Mar 7, 2004
    #20
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