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Is this due to RoHS solder?

Discussion in 'Electronic Repair' started by Boris Mohar, Dec 8, 2011.

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  1. Boris Mohar

    Boris Mohar Guest

  2. Paul Drahn

    Paul Drahn Guest

    It does look pretty bad. However, the cracks may not go very far into
    the solder. You would have to carefully cut one of the connections apart
    across a break and see haw far it does go.

    When was the part manufactured. RoHS was not required until July 1996.
    There have been many different formulations of lead-free solder. Most
    have problems of one type or another. This could be one of the solders
    that was discontinued for just the reason you see.

    Paul
     
  3. N_Cook

    N_Cook Guest

    RoHS came in with a vengence 2006, the earliest I've seen it in anything was
    2001.
    If you have some known tin+lead solder try adding it to a joint with a
    soldering iron. If the surface goes white and the surface "freezes" almost
    instantly then the original joint was likely PbF. If the original was
    tin/lead then a near enough normal leaded solder joint will result. If you
    have a temp settable soldering iron and set it low enough to still create a
    leaded solder joint then you may find it takes an awful long time and
    produce a pastey looking lump if you try the iron on a PbF solder joint with
    a bit of flux to give it a decent chance of melting.
    Just by appearance I would say you have PbF
    This is a known PbF crack developing, in the body of a joint rather than
    around a pin , a pic of mine
    http://www.diverse.4mg.com/talk_crack.jpg
     
  4. I was just going to ask how to identify RoHS but this thread made it
    unnecessary.

    I am now looking at an Antec PSU with no date except "copyright 2004."

    I will try it.

    That's exactly the kind of test I was going to ask about! Thanks.


    --

    Reply in group, but if emailing add one more
    zero, and remove the last word.



    ..
     
  5. Charles

    Charles Guest

    "Boris Mohar" wrote in message


    Took apart a Volvo 850 fuel pump relay. Cracks everywhere.


    Some of the responses to your post are misleading. The dull, grainy look is
    normal with lead-free solder.

    The cracks are not necessarily a fault. Surface cracks that we can see,
    often do not extend deep enough to cause problems.

    In any case, soldered joints have indeed been compromised by the new
    "improved" lead-free alloys!

    Mixing politics and engineering will almost always yield bad decisions.


    ..
     
  6. Boris Mohar

    Boris Mohar Guest

    Indeed. I have resoldered and brought back to life many of the white ones.
    They were not RoHS, nevertheless the solder failed around relay armature
    pins.
     
  7. N_Cook

    N_Cook Guest

    Ignoring potentially dangerous chemical test here is another physical test,
    perhaps not so conclusive.
    Find a stainless steel sewing needle, must be st/st not ordinary steel. Try
    poking the needle in a soldering iron made , molten pool of leaded solder ,
    pulling out, with a blob on the needle.
    Pull off using just a fingernail usually.
    Repeat using PbF and you will probably need 2 pairs of pliers to pull the
    blob off the needle
     
  8. N_Cook

    N_Cook Guest

    This is why the likes of the aviation industry has a derogation to allow
    continued use of leaded solder. Fuel pumps etc with PbF on a plane will soon
    have them falling out of the sky.
    They then have the problem of sourcing guaranteed PbF-free componentry ,
    only single type production lines (PbF) around these days , generally
    speaking , so insentive (serious mark-up) for a lot of fraudulent paperwork
    and manifests etc , declaring the items are leaded when they are actually
    PbF
     
  9. Charles

    Charles Guest

    "N_Cook" wrote in message
    This is why the likes of the aviation industry has a derogation to allow
    continued use of leaded solder. Fuel pumps etc with PbF on a plane will soon
    have them falling out of the sky.
    They then have the problem of sourcing guaranteed PbF-free componentry ,
    only single type production lines (PbF) around these days , generally
    speaking , so insentive (serious mark-up) for a lot of fraudulent paperwork
    and manifests etc , declaring the items are leaded when they are actually
    PbF

    It would be nice to live in a structured society where the governing system
    reacts, but never over-reacts. And, this is really a dream, where
    governments act proactively, before things go to shite.
     
  10. Smitty Two

    Smitty Two Guest

    Since my ears were burning, I'll toss in my tuppence. Looks to me like
    leaded solder, poorly put together. Insufficient heat and or dwell time,
    and insufficient flux. Looks hand-soldered to me, and looks as though
    the assembler tried to compensate for insufficient heat and flux by
    applying excessive solder.

    Sure, the thing's in a hostile environment, and that could lead to
    cracking, but the quality of the joints was never good, which makes them
    more susceptible to hostile conditions.

    My shop used to be across the street from my car mechanic, and he
    brought me some god-awful automotive stuff. Don't remember which make it
    was, but for years they used a relay board (box into which all the
    relays plugged) that was an absolute abomination. Essentially about 10
    layers of folded plastic with traces and pads on one side, all stacked
    up together. A multi-layer "board" with god-awful soldering that just
    could not be repaired after a few years of exposure to corrosives.
     
  11. N_Cook

    N_Cook Guest


    PCB holes somewhat larger than the component pins always, given time, would
    cause ring cracks in solder but with PbF occurs in just a year or two. For
    things like pcb mounted multi-terminal transformers they could have an extra
    machining stage. A conical grinding or milling stage, per hole, on the side
    that accepts the component so that larger holes could be avoided and still
    not mess-up the hand alignment/placement due to microscopic , but in spec,
    misalignment of the pins
     
  12. Boris Mohar

    Boris Mohar Guest

    Relay armature, diodes and resistors on this board are all clad Iron.
     
  13. Date of manufacture 1996, so it's 16 years old. What do you expect?
     
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