Loose/wiggly terminal

  • Hey!

    I've been using my Duet 2 Wifi for over a year now, and i've recently switched PSU and noticed that the terminal for power input is a bit loose, see video; https://imgur.com/a/kRqVD5B

    Is this something i should be worried about or is it normal?

  • Definitively check out the solder joints of the connectot. Note that sometimes it is very difficult to see a bad solder joint - so look very carefully!.

  • Just took a quick look, it's kind of a hassel to unwind everything but it all looks good - as far as i can tell. VIn is stable at
    24.2 when idle.

  • Yeah sometimes the terminals aren't seated properly when installed other times they loosen due to thermal cycling but unless the solder joints are affected it shouldn't pose a problem.

    But as pointed out its not always easy to spot bad solder joints.

    If the wires are noticeably warmer near the boar than say near the power supply or on the bed wires then that would suggest an underlying problem. Or discolouration on the board or wires nearby is also a tell tell sign.

    If you happen to have two soldering irons, a second set of hands and some flux you could just slap some flux on, heat up both joints and reseat the connector while reflowing the joints to be on the safe side. Doing it alone without more specialized tools can be a bit of a challenge though, likely removing it and cleaning up the pads and pins first being easier.

  • I can't see any discolouration or any sign of something being bad.

    Resoldering the connector is a bit out of my league, unfortunately. I'll probably make it worse, lol.

  • You will not necessarily see anything when looking at Vin and a 'quick look' will not tell you a thing unless it's a very obvious issue.
    There have been a number of reports of overheating (due to bad solder joints or poor wire contact) and in some cases the solder didn't properly wick up the through hole.
    It is not uncommon to only see a bad solder joint through a careful inspection with a magnifying glass.

    Some wiggle is to be expected but if you have any doubts it is well worth doing a thorough check.

    An alternative to taking everything apart and as a interim stop gap measure, if you have an IR thermometer, occasionally measure the terminal temperature and if there is a noticeable increase then you know that there is something going on.

    You did use ferrules over the power wires ... right ????

  • Yes, i've been using ferrules since day one.

    My guess is that it's caused from over-tightining the terminal..

  • Good to hear about use of ferrules!
    Over tightening does not affect wiggliness.

  • Moderator

    If you have the board out, can you post a photo of the backside of the terminals?

  • Thanks for the replys!

    I have now taken the board out and recorded some more videos and added some images: https://imgur.com/a/8NW6E3q

  • administrators

    That's definitely not right. When you wiggle the terminal block, do the pins poking out of the bottom move too?

  • Yes, the pins move, see new video: https://imgur.com/a/drSCZRG

  • administrators

    Thanks. The connector definitely needs to be re-soldered. Using the board before that is done may damage the PCB.

    Soldering those terminals requires a high-powered soldering iron with the correct size bit.

  • Re-soldering is out of my comfort zone, I'd probably mess it up.

    Any recommendations where I could get it fix in EU?

  • administrators

    @jontek2 said in Loose/wiggly terminal:

    Re-soldering is out of my comfort zone, I'd probably mess it up.

    Any recommendations where I could get it fix in EU?

    Which part of EU?

  • @jontek2 said in Loose/wiggly terminal:

    Any recommendations where I could get it fix in EU?

    I'd try a makerspace or something like that if you have something locally. But given the current "situation" they might be closed down and shipping will be slow and potentially costly.

    Failing that maybe see if you have a friendly neighborhood repair hero near you? https://forum.duet3d.com/topic/13875/community-repairs

  • Gothenburg, Sweden

  • Just moved here so not so familiar with the local alternatives.

    I'd have no problem sending it for repair, can't be that expensive.

    The other alternative is to buy a new board..

  • @jontek2 said in Loose/wiggly terminal:

    , can't be that expensive.

    about NOK 70 for the return postage if you send it to me, but best be quick about it as we're on borrowed time with new customs rules around the corner that could mean import costs at 25% + 165NOK. This was due april 1st but postponed without any clear date.

  • @bearer is a hero and is helping me with the repair. Big thanks!

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