External driver extension board failure



  • i recently bought a eternal driver board as I am going to be using external drivers. After verifing everything was wired right for the 3rd time i decided to fire up the controller with 24 volts from my main powersupply including to the external drivers. 2 of the converter chips on the external driver board burst into flames disabling power was enoug to kill the flames but I was glad I alway do a visual chexk of my electronics the first time I fire them up. No pun intended. I have new chips ordered and hope it was just 2 faulty chips. I used a ramps board and drivers appear fine so we will see. Just a warning if you use one of these boards. Im not sure if I got lucky and got 2 bad chips which happens or if something else happened or the moon and stars were all in alignment. https://photos.app.goo.gl/WoYXcigcCLTL3arD9
    https://photos.app.goo.gl/9B7ry7wSKai7Hku9A



  • @IdahoCastleman which external drivers did you use and how did you wire them? Did you check the switch settings if they have any?



  • @JoergS5 yes they are tb6600. They were connected to the last 6 pins on the stepper driver. The plugs on the board were verified several times to be the same. I have never seen chips ignite on fire like these. No usual pop like you usually get and with only 2 dying it just seems wierd. Link to driver. https://smile.amazon.com/dp/B07HP1GKLB/ref=cm_sw_r_cp_apa_i_ctXkFbRZB00EV



  • @IdahoCastleman when thinking about it, I don't understand how this could happen, as only the low current of step/dir is flowing through the board.

    Could you explain the wiring of the components, can be through image?


  • Moderator

    From DC42: "2 possibilities I can immediately think of: (1) those 2 chips were fitted the wrong way round, in which case they would blow whether or not the external drivers were connected; (2) external drivers connected incorrectly, so 24v was fed into the outputs."

    So some further photos and details could help.



  • I tried replacing the chips myself but unfortuantly the boad was damged prettygood as well. Im not sure the orientation. Since the board was damaged I have ordered another one. At this point I think Im going to blame operator error. I thought I would share to make sure if it was quality issue such as mention chips backwards or bad product that the issue was logged. I am interested in seeing of Duet is a valid cnc setup or if I shod just keep it for 3d printing as another printer is in my near future.



  • @IdahoCastleman I suspect that you made a connection where the current which is used for the steppers was routed through the board somehow, so a picture of your circuit or an image would be helpful to see whether it can be avoided with the new board. Maybe you connected the ground for step/dir and stepper, which is not necessary with the TB6600 (it's opto coupled) and you had a ground loop. But to see what could be the reason one needs more information about the wiring.


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