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DFP cabling, Pendant moving, SOLVED.... part 3

Discussion in 'Electronic Design' started by Existential Angst, May 1, 2013.

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  1. Holy shit.....

    Previous DFP cable extensions didn't work (not well, at any rate), dfp-dvi
    adapters didn't work (with DVI cables as the extension), dfp gender
    changers/hardware almost don't exist.....
    DVI cables seem to be pinned every way to sunday. And even if they were
    pinned "correctly", the dfp-dvi *adapter* is hobbled from the gitgo because
    my dfp cables are 26 pin, and DVI cables (dual link) are 24 pin, so even
    with the "proper" adapter, you are short 2 pins. And then, there is *at
    least* one dummy pin on dvi cables, sometimes 10 dummy pins....
    So at best, you are short 3 pins, and there is no way of telling what those
    missing pins are doing/not doing.

    I was actually at the Microcenter pyooter store, with my dvm, ringing out
    various dvi cables for their dummy pins, finally concluding that dvi cables
    were simply not going to work as a substitute for 26 pin dfp cables.

    The 30 ft dfp replacement cable (nonHaas) worked, but yielded a
    significantly degraded image, and the dvi's yielded, well, NO image!! Some
    pretty blinking colors but no image.

    An effing nightmare, and an expensive one.

    So the solution turned out to be:

    NJ Haas just happened to have an oem 13 ft dfp cable for the GR510 lying
    around, and for a mere $120, they gave it to me. Had they not had it, it
    proly would have been weeks to get it from CA Haas.

    We took off one connector on each end (the original and the newly-bought
    cable), and spliced the two cables together.
    No mean feat, let me tell you. And not a special cable, either. 13 pairs
    of 28 ga wire, nothing apparently special, I don't know if the wires were
    even twisted pairs. The whole bunch shielded.

    Splicing dat cable was *a muthafucka*, took two of us HOURS to do the job,
    with multiple soldering irons, vises all over the place, continuity testing
    *up the ass*.... very time consuming, very niddly work, very easy to make
    any number of disastrous errors, pinout-wise.

    Hint to the brave: don't even *think* about a splicing job like this
    without a fine low-watt soldering iron and **separate flux**. Flux-core
    solder is fine for some stuff, I spose, but separate flux makes all the
    difference in the world for fine stuff, allowing you to instantly tin the
    wires, which then makes joining MUCH easier and more reliable, AND
    shrink-tube friendly..

    When all was done, the screen image was absolutely PERFECT. I swear to god,
    we could have spliced TEN cables end to end, with no image degradation!!

    So I don't know what was up with these other goddamm cables, replacements,
    but had I known the difficulties in all this, I would have gone the Haas
    oem/splice route from the gitgo. A tremendous learning experience.

    This pendant re-location cost me a goddamm fortune, when all was said and
    done, proly $1,000 *just to move a goddamm pendant 15 feet*!!!!! Jesus H.
    Christ.....

    My advice to anyone else doing this is..... well, I don't know.... all
    these cables were a fuknBUST, and I don't know why, AND cable-splicing is no
    joke either, bleeve me, so the allure of just buying cables off the shelf
    strong indeed, BUT it can prove very costly.

    But splicing seems to yield an almost *guar-own-teed* result, IF you splice
    *working OEM* cables.

    If splicing, you MUST check the pinout of EVERY wire splice as you go along,
    to make sure there are no mistakes -- much easier said than done, as it's
    not mechanically easy to probe the contacts on some connectors, ESP dfp
    connectors. I had to use a #75 drill on the probe to "get in there". And
    two people make the job much easier, both the pinouts and soldering itself.

    You then have to "protect" yer completed cable splice, also much easier said
    than done. We had to cut and modify a 2x4 electrical "handybox" and modify
    romex connectors to ensure the ground AND strain-relieve the splice itself.
    What a fuknPita.

    But the result was perfect, screen/image-wise, absolutely perfect, ZERO
    degradation. End of a nearly two-week very costly drama/nightmare.
    Just today's effort, which included picking up the Haas cable and other
    materials, was a whole day for two (very motivated) people.

    Heh, now I know why Haas balked at relocating the pendant themselves....
    LOL
     
  2. I will slit my wrists if anything goes wrong with that cable!!

    Zinc Chloride (plumbing flux) does splendidly!
    Well, it will do as fancy as the cadcam you program.
    In my case, since I use only graph paper, it's not fancy at all, just long
    wide stuff.
    But which saves enormous time/trouble over finagling in a smaller vmc.

    I'll actually be "publishing" the design of my stuff, as "defensive
    publishing", patent-wise.
    See Don Lancaster on the uselessness of patents. PLenty of vids, as well.
    --
    EA
     
  3. tm

    tm Guest

    That's not good. When it fails, you will know where to look. Zinc Chloride
    flux is a bad thing to use on small wires. It will corrode your connections
    over time.

    Since you buzzed the cable out as you built it, did you document all the
    connections? Maybe you can get some cable and connectors and make up a
    continuous cable without any splices to have ready for the future.

    Good luck,
    tm
     
  4. Fred Abse

    Fred Abse Guest

    On electrical connections?? Kerrist!

    ZnCl plumbing flux is acidic, and *corrosive*. NEVER use it on electrical
    work.

    Expect your joints to disappear over time.
     
  5. If that's true, I indeed wish you hadn't told me.... :(

    But really, ZnCl2?? I figgered that would be as mild as they come.... I'm
    surprised it even acts as a flux!!
    Sheeit, you can EAT ZnCl2.... iirc, it's what's multi-vitamins..... lol
    Dat old 2x4 handy box -- attached the "wrong way" -- shore does mucky up my
    nice cable.... LOL
    Actually, I'd be a pill kind of guy, if it came to that....
    But really, if it does come to that, ahm takin hoards with me.... all from
    Wall Street....
    Well-organized, eh??? LOL Not Lancasters strong point!!!
    But really, if that was you, thank you for that. What an eye opener!!!
    Really, some of the most original thinking/exposition I've read in a long
    time.
    ..
    And after reading alladat, I STILL headed for the patent route anyway, until
    real reality reared its very ugly head, which became crystal-clear bec of my
    Lancaster readings. A lawyer that was recommended to me sent me a whole
    bill of patent particulars, and man, it was like reading a Riot Act.... I
    said, Holy Shit, Lancaster is more correck than he proly knows!!!!!
    Getting into that patent shit is like being into a loan shark with a vic
    that never ever ends. Sorta like fukn Domain Names.... what a trap DAT
    is!!!!!

    Don Lancaster pointed out that patenting your own stuff can also hamstring
    you with your own effing product!! Not likely, but one of many possible
    scenarios.

    Really, one of the great things I've learned on the web. The other being
    Edison circuits, when I was converting all my fuse panels to breaker boxes,
    and found that every fukn one of them was wired incorrectly!!!!!! And I had
    a bunch.... with cloth-covered #14 wire.... it's a miracle my house is
    still standing!! On alt.home.repair, from that guy Fretwell, iirc.
    knowledgeable guy, a life/house-saver, in my case.[/QUOTE]
     
  6. "Bruce L. Bergman (munged human readable)"
    Dayum -- universal consensus on ZnCl2.....
    No herculean effort goes un-sabotaged, eh??

    Well, all good advice all around. It's working now, when I can breathe,
    I'll arrange for a more permanent solution.
    I don't know if Haas can accommodate me, since these cables are almost
    f'sure subbed out and rare to begin with.
    What I can also do is eventually find the female PCB/board connectors, and
    make my own gender changer/coupler.
    And buy two new cables!!

    Or, I can just re-splice.

    It looks like my new re-located pendant is going to be the gift that keeps
    on taking....
     
  7. Fred Abse

    Fred Abse Guest

    You can drink ethanoic acid, AKA acetic acid, AKA vinegar, too, but
    that'll see off electrical joints, as well.

    Voltages make the reaction aggressive.
     
  8. tm

    tm Guest

    Look at the bright side. It was an educational experience. Most pay much
    more for that.
     
  9. ALL electrical tech manuals warn against acid fluxes and acid core
    solders in doing electrical joints. Surprised you didn't know that.

    It's going to fail, just a matter of WHEN. Best cut the joint out and
    redo it properly. You CAN get tinning pastes that have solder and
    paste flux ground together, sold for tinning irons but not limited to
    that. RS has a quarter-sized tin of that for $5-6 bucks, works well
    for the intended purpose and I've used it for doing really fine
    stranded splices. It's intended for electrical work, too, so has
    activated rosin flux, the ONLY stuff that should be used for
    electrical work.

    As to the failure mode, they don't call it ACID flux for nothing.
    Zinc chloride attacks copper, which is why you get that fine and easy
    tinning from it, it dissolves oxides and a bit of the copper, leaving
    a nice chemically clean surface for the solder. Unfortunately, it
    just doesn't disappear. Those chlorides keep eating and those fine
    wires will disappear as blue-green sludge, sooner or later. It'll
    wick up the inside of the insulation as well, so don't leave it too
    long or you'll be chopping out more than you want.

    DVI cables have a number of standards, some for analog video, some for
    just digital video, some for analog and digital video and some for two-
    channel and bidirectional. If you don't like one, you can always find
    another. But you DO have to pay attention to the tags on the bag or
    wrapper. And sometimes they lie, too.

    For doing those computer-type cables, I made up a jig many years ago
    that uses a couple of wooden snap clothespins glued to a wooden base.
    Works well for a third and fourth hand. A later version I made up
    allows one pin to slide for joint alignment.

    Stan
     
  10. Yeah, Don Lancaster, Edison circuits, and now Don't use Zinc Chloride....
    <groan>

    Not disputing that I've got an eventual repair job ahead due to zinc
    chloride, but zinc chloride is not, afaict, an *acid* flux.

    It may be corrosive, but not bec of acidity. The following reaction proly
    explains the corrosion:
    Zn(2+) + Cu(0) ---> Zn(0) + Cu(2+),
    ie, Cu metal (Cu(0) ) is going "into solution" or iow, dissolving.

    So nothing really acidic about this, but still corrosive, over time.
    The reason corrosion does not occur more quickly is because Zn is "higher"
    in the electrochemical series, and when Zn(0) forms, it tends to shoot back
    its electrons to Cu, keeping Cu intact -- for a time. But eventually the
    statistics of the equilibrium do wear away the Cu, apparently.

    If the chemistry were reversed, ie, the wire were Zinc metal, and the flux
    CuCl2, the corrosion would proly be complete in mebbe a matter of hours or
    days, bec
    Zn(0) + Cu(2+) ----> Zn(2+) + Cu(0)
    would proceed forward until completion, ie, no more Zn metal, again, for the
    same reason, that Zn is higher in the electrochemical series, driving the
    reaction forward to completion.

    Nuthin like ad hoc realizations..... ad hoc = Too Late, in this case.
    <sigh>
    --
    EA


     
  11. Was it ever DFP in the first place as wiki has DFP as 20 pin
    http://en.wikipedia.org/wiki/Digital_Flat_Panel not 26 pin so maybe a
    Haas special on a similar connector.
     
  12. Denis G.

    Denis G. Guest

    I haven't used them, but the "About Us" section says that they will
    make custom cables:
    http://cablesandconnectors.com/
    Might be worth a shot.
     
  13. yeah, it's not a big deal.

    It will be much easier to resplice the cable later once you know what do
    do. I love forgetting a piece of heat shrink tubing or strain relief
    netting stuff and having to start all over again when redoing connectors.

    Telco guys have no problem splicing hundreds, even thousands of pairs,
    they have some cool tools, but it's still a manual process to line things
    up. It's the same for fiber, but that stuff is more fragile.
     
  14. Oh, fwiw, by virtual chemical definition, ZnCl2 is a *salt*, just like
    sodium, potassium, calcium chlorides.
    And all are indeed corrosive, albeit in a variety of ways.. NaCl corrodes
    concrete!
     
  15. tm

    tm Guest

    Yes, it is a salt but dissolved in water, it becomes quite acidic. A 6M
    solution will have a pH near 1.0.
     
  16. That's like 800 gm in a liter of solution!!! Is that the approx.
    concentration of flux??
    The Merck gives a pH of 4 of aqueous solution, proly less than 1 M, but, as
    you say, still substantially acidiic... go figger.
    Yet NaCl forms a neutral solution..... go figger.
     
  17. tm

    tm Guest

    It probably is a near saturated solution. ZnCl2 is highly water soluble. It
    is made by dissolving zinc metal in hydrochloric acid. They might even stay
    on the acidic side by limiting the zinc added.

    You sound like you have a chem background.
     
  18. DoN. Nichols

    DoN. Nichols Guest

    [ ... ]
    Anti-wicking tweezers can make a big difference there. But yes,
    I prefer crimping, myself.

    Enjoy,
    DoN.
     
  19. DoN. Nichols

    DoN. Nichols Guest

    Yes -- Heathkit would void the warranty on any kit assembled
    with such a flux.
    Good plan.

    Enjoy,
    DoN.
     
  20. Now, everytime I look at my crystal clear screen/splendidly re-located Haas
    pendant, all's I can visualize is my chemically crumbling splice -- all 26
    of them.... LOL
    No breaks, no breaks....
     
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