L1 released the magic smoke

  • I've done something boneheaded when wiring my Smart effector and inadvertently connected the ground pin of the input 2 (z-probe) connector to the negative side of my hotend wiring instead of actual ground. This had the unfortunate effect of backfeeding 10.8 volts through the heater and into the effector, causing L1 to rapidly release it's smoke once power was applied.

    Miraculously, it seems perhaps the rest of the circuitry has escaped unharmed. Everything visually appears ok, and I was able to carefully supply a proper 3.3v and gnd from my bench supply and get the green light to flash with some light pressure/tapping on the board.

    I'm not quite sure of the purpose of L1 (other than being a crappy fuse in my case), I'm hoping someone can tell me if it's particularly critical to proper operation (in that case a value or part # would be excellent), or if it can be safely bypassed (I have plenty of smd jumpers and resistors of various sizes and values, but no inductors onhand), also the L1 pads are gone so I'll have to do some surgery to properly replace it.


  • administrators

    L1 is a ferrite bead that acts as a fuse as you discovered, and helps avoid the wires to the Smart Effector radiating EMI. It's not critical to the operation of the effector.

  • Thanks, I got the new effector reinstalled last night after repairing the trace, and confirmed it's working fabulously!

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