Replacing bad caps

Discussion in 'Epox' started by Lee MacMillan, Feb 27, 2008.

  1. My 8RDA+ just died presumably due to the bad caps (they are bulging,
    leaking). After months of taking 2 or 3 tries to boot (good a "no video
    signal" error message and never saw a boot screen), it finally would not
    boot at all. I put in a spare 8KHA+ and am up and running again. Wondering
    if anyone has successfully replaced the bad caps and got a dead mobo working
    again?
     
    Lee MacMillan, Feb 27, 2008
    #1
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  2. Lee MacMillan

    Paul Guest

    The idea is, to replace them, BEFORE some other components
    get damaged. When a cap fails completely, there can be
    collateral damage. (Do a visual inspection.)

    Generally, if you're going to recap the board, you should
    do it when you see the first cap bulging. You can do all
    similar ones at the same time, because the others presumably
    are not far behind. Sometimes you get lucky, and the board
    is a mix of some good quality ones and some bad ones, and
    you save a few bucks by only doing all the bad quality ones.

    I wouldn't say, that pulling caps out of a board, is my
    favorite task. The problem is, the cap may be soldered
    to a solid copper plane, and those soak up the heat from
    the soldering iron. Sometimes, it is hard to get enough
    heat into the solder joint, to melt it.

    One of my former employers had a good idea. In the design
    tools, the holes for capacitors were made over sized (bordering
    on sloppy). It made it dead simple, to remove and replace a
    cap. Another place I worked, some genius set the hole size,
    for a close to interference fit. That made working on PCBs
    pure misery. Stuff was very hard to get out, even with
    a vacuum desoldering station.

    HTH,
    Paul
     
    Paul, Feb 27, 2008
    #2
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  3. There are only 5 caps that are bulging, the 4 tall ones in a row and one
    other. I may give it a shot just as an academic exercise. If it doesn't
    work, I've only out a few bucks for the caps.

    Thanks.
     
    Lee MacMillan, Feb 27, 2008
    #3
  4. Lee MacMillan

    Zyp Guest

    I replaced the failing caps on my 8k7a+. Still working. I removed the old
    caps [easy], drilled the existing holes out with a pin vise [available at
    most hardware stores - ] and used a #60 drill .. just the right size for
    inserting the caps and soldering.
     
    Zyp, Mar 1, 2008
    #4
  5. I removed the 4 worst ones yesterday without much problem. I can even see
    light thru the holes but I don't think the are big enough for the leads on a
    new cap. Upon closer examination, I see 5 or 6 more that are bulging a
    little but not leaking yet. Haven't decided if I want to bother yet but
    thanks for the tip.
     
    Lee MacMillan, Mar 2, 2008
    #5
  6. Lee MacMillan

    Zyp Guest

    yw - Good luck
     
    Zyp, Mar 3, 2008
    #6
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