KRC2 pendant extremely dim

    The screen is SLIGHTLY brighter indeed.
    But the robot is COMPLETELY useless...


    I have been getting warnings of low battery voltage for some time.
    Could that be the reason why the robot does cold starts instead of just getting out of hibernation ?
    Like there is just enough juice to save the mastering data, but not enough to finish the hibernation procedure.


    And damn ! How can the drives stop working in manual mode after the first triggering ?
    This makes absolutely no sense !!!


    Time to re-install ?

    Don't act on impulse - THINK before you do...



    Consider following:
    * Robot is a machine and it REQUIRES maintenance (just like your car needs new tires, brakes, oil etc.). Batteries are consumable and need to be changed periodically
    * If problem did not exist before you opened KCP, it is extremely unlikely that problem is elsewhere. in other words there is no reason to consider reinstalling software, replacing hdd or robot motors or doing mastering, etc.
    * if you ever try to work on some electronic device, you need to get training and - you need to be a lot more careful. there is a lot of things that can go wrong. ripping out connectors, not noting where the connections were before something is disconnected etc is a road to disaster.
    * if the only thing you messed with is KCP, why not try another KCP?

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    Well, for my defense, I did ask for some advice on June 10th, and only got an answer after bumping the topic on July 31st.
    I have looked very hard for ANY picture or description of the inside of a KRC2 KPC and found absolutely nothing.
    This is why I took the time to document what I did, hoping that it could help others.


    I don't have the money to get an official KUKA training, so I do what I can with friends and forums...


    Also, I really don't see what the pendant has to do with the forced cold starts.
    I'd love to try another KCP, but it's like 1000 carat diamonds, I don't have many lying around.


    Just so that you don't think I'm a raving madman at the helm of a massive industrial robot, Wall-E is a Little Kr6 which runs about an hour a week, therefore I didn't feel the urge to sell a kidney for some KUKA folk to change the oil.
    The batteries are shipping as I write this.

    Edited once, last by Wall-E ().

    Quote from SkyeFire


    You should never get an "Active commands inhibited" message without another message that inidicates why.


    Except for the 6D mouse, apparently.
    I once bumped it, got "active commands inhibited", but the actual warning message did not remain in the log, it disappeared. Flashed briefly.

    Really? Hm... given that the broken copper strip attaches to the Mouse, that makes sense. I always avoided using the mouse, since I never had the dexterity to make effective use of it, so I've never encountered that before.


    So, would the "vanishing" message still be present in the fault log? Wal-E, I would suggest you open up the Logbook and see what errors share nearly the same time stamp as the "Active Commands Inhibited" error you're seeing.

    Quote from SkyeFire


    You should never get an "Active commands inhibited" message without another message that inidicates why.


    Err... well, this is the twilight zone then.
    And how about the cold starts ? In what circumstance would the system not do a normal restart after a "hibernate" ?

    I think that I found what's going on with the pendant and dead man switches.
    I noticed that the small dead man switch which is on a sort of cylindrical bump had a strange behavior : when pressed, it did nothing, and then if you press harder it switches on the display of the "X, Y, Z, etc... or A&, A1, A2, etc..." options.
    Normally, that second level should also be an open circuit, as with the other dead man switches.
    So I checked the ribon cable, and found that it was squished on the edge, certainly it was sandwiched on the nearby screw socket that secures the case closed.


    EXACTLY what Spirit 532 warned me about.


    Now here come the big question : what is the reference of this ribbon cable so that I can purchase one, (either 0.8$ on Ebay, or 245 $ from KUKA) :icon_smile:

    For one, no - the second(fall-through) level of the deadman switch is not open circuit. It's a separate panic state that acts like a softer e-stop, and it can be seen in the ESC diagnosis tool.
    And second - good luck, lol. You're never going to find this specific ribbon cable on eBay. Best you can hope for is just cutting off the damaged portion and rejoining the remaining two halves. Maybe adding an extension of the same wire count can help. But I don't recommend you do it, because it seems like you don't have any experience in electronics, and repairing a thin, multi-strand ribbon cable is far from easy. Take it to an electronics shop instead and ask them to do that for you.

    Hm... might it be possible to simply disconnect that ribbon cable entirely, and work with just the "long" deadman switches? I don't know if the pendant needs a continuous connection through the buttons on that back-panel post, or if it just monitors their open/closed state.


    I couldn't get a good look at the board connectors on either end of that ribbon cable, but if it's just male pins on the circuit boards, assuming the spacing is standard, you might be able to make do with something like this: https://www.adafruit.com/product/1950. Assuming there's room for the height of the connectors. You simply peel off the correct number of wires as a separate "ribbon" cable. Really depends on just how tight things are inside the pendant.


    It's possible that KUKA used a regular, off-the-shelf ribbon cable here -- you might be able to find a close-enough match on the open market, but you'll need to really nail down the specifics of what you're looking for. Ribbon cables tend to have a nomenclature all their own, and I'm certainly not up to speed on it. Digi-Key or Mouser would be good places to start looking.

    where is the cable damage exactly?



    ribbon cable is cheap and you can get it per meter (or cannibalize old IDE cable)



    i agree that you should not be attempting things yourself (or practice on something else first - before you wreck KCP)

    1) read pinned topic: READ FIRST...

    2) if you have an issue with robot, post question in the correct forum section... do NOT contact me directly

    3) read 1 and 2

    I might be able to get one from Eurobots from whom I pruchased it, I guess they have heaps of hardware for canibalistic purposes.


    I also found this interesting video : https://www.youtube.com/watch?v=RyRVA7NDo9o


    I'll be more prudent next time, but there is not so much clear and visual tutorials out there for robot hardware repair, unfortunately.
    At least, if this whole adventure can help out poor souls like me in the future, it will be a positive thing.

    Edited once, last by Wall-E ().

    After further testing with an Ohm-meter, I saw that the current still flows through the cable ; only the plastic is a bit damaged, and I could fix this easily.
    But then I realized that one of the pins of the connector on the motherboard was bent so that it didn't connect to the corresponding cable.
    Things are back to normal now !


    I made a video out of the little tutorial, and added extra warnings in the description : https://www.youtube.com/watch?v=YpKQYHMVEhA&feature=youtu.be


    But as Panic mentioned : it's better to think twice when undertaking this kind of task for the first time !

    Edited once, last by Wall-E ().

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