Duet Wifi external antenna upgrade - damaged SD socket latch



  • Hello,

    With the help of a friend, we had a go at modifying a three of our Duet Wifi's to have an ESP-07S with an external antenna earlier today. In general, all went well, and the boards are back up and running with much better signal.

    However, on two of them, it appears the latch function of the SD card socket has died 😞 We can tape the card in, and it still reads/writes absolutely fine, it just won't stay in of its own accord.

    My guess is that we either overheated part of the socket, or got some excess flux in the mechanism. From what we can see, the latch mechanism seems to move like on the working board, it just doesn't 'click' in.

    Does anyone have any experience of this issue, things to try/test etc, or is the onlly real solution to replace the SD socket as well? If there is something we've messed up, would be good to make a note of it in DC42's guide (https://forum.duet3d.com/topic/2825/converting-the-duet-wifi-to-use-an-external-antenna) to save others the same fate!

    Thanks



  • Here's a picture of the not-working socket. There is a bit of stray solder on the side of the socket - evidently we didn't have steady enough hands!

    20200713_235712.jpg



  • could be either temp or flux I guess. some kapton tape is always convenient to shield surrounding parts from heat.

    (its worth noting that he sd card socket is made to be reflowed so it should be good for around 250C for up to 60 seconds or somewhere in that ballpark, so it can really take a bit of heat)



  • @engikeneer said in Duet Wifi external antenna upgrade - damaged SD socket latch:

    ears the latch function of the SD card socket ha

    ++for kapton 🙂

    as for flux, washing that part with alcohol (ipa or ethanol) should clear it up, but flux would make it "sticky" not "not working" imo ..

    I hate those sockets 😞 I had them stop latching out of the blue without any soldering near them 😞 (not on duet boards, on my own boards, good sockets from digikey/farnell 😞 )



  • Yeah kapton would have been a good idea... we had a coin over it as a heat sink but maybe the hot air still managed to get round that. We probably also ran the air a bit hot (it was over 400 C). Ah well...

    Any ideas on if I can easily remove/reduce the spring force? Would be easier to keep the SD in place with tape if it wasn't spring loaded, but I don't want to damage it more and risk it stopping working


  • Moderator



  • I'd get some circuit board cleaner in an aerosol can and a soft toothbrush and give it a good clean first. Both around the solder joints and inside the sd socket as well.

    It can't hurt to try, and it will be a better job than having that flux there.



  • Thanks everyone for the replies. I've got some more circuit board cleaner on order so will give that a go but am not holding out much hope. One day I'll pluck up the courage to replace the SD socket and have a look inside to see what damage I actually did!



  • @engikeneer that happened to me, i did even worse and broke some of the solder points....but is no big deal the pinouts for the duet are well documented and the SDcard is SPI if i recall, so i just followed some traces to make the connection work again...just study the boards circuitry before you do anything else



  • all the design files and schematics are available for the the duet2 (poke around for older revisions)
    https://github.com/T3P3/Duet/tree/master/Duet2/Duet2v1.04

    ^-- if it suffers bitrot in the future try https://github.com/Duet3D/


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