New BLTouch not triggering.

  • Received a new replacement Duet2Wifi board and everything is working, except for the BLTouch. I have tried two different BLTouch's and I am having the same problem with both. When homing Z the probe touches the bed, retracts, then extends again and acts like it is in error mode, while the Z continues moving down to the bed.
    M280 P3 S160 I1 resets the error mode.
    M280 P3 S120 I1 Self test works.
    M401 will extend the probe.
    M402 will retract the probe.
    It is wired as described in:

    config.g; Z-Probe
    M574 Z1 S2
    M307 H3 A-1 C-1 D-1
    M558 P9 H5 F120 T6000 R0.2 Note: I've tried setting P9 to P3.
    G31 P500 X-28 Y5 Z2.1
    M557 X10:220 Y10:220 S40

    M280 P3 S10 I1

    G1 Z5 F6000 S2
    G1 S1 X-240 Y-240 F1800
    G1 X5 Y5 F6000
    G1 S1 X-240 Y-240 F360
    G1 X38 Y20 F6000

    G1 Z5 F6000 S2
    G1 X38 Y20 F6000

    M280 P3 S90 I1

    What am I missing?

  • Does the nozzle crash into the bed the second time?

  • @gtaman
    Yes it does

  • did you just switch the BL touch out without changing the wires? because I have a feeling a wire is broken and only works sometimes. And make sure you have two pins between the orange and brown connection.

  • @gtaman
    Thanks gtaman
    That was mostly right. I left the meter long extension in and upon inspection, the Dupont connector on the BLTouch end of the meter long extension had a couple of broken tabs. I like that the BLTouch comes with spare Dupont connectors. Working now.

  • @keith

    Haha awesome! My buddy had the same problem with his $5000 printer. He'd been calling tech support for over half a year, and their only way of solving the problem was replacing all the electronics. I came over one day, noticed it only works on some parts of the bed, and figured it was a broken wire within the same day. Depending on the position of the axis, the wire would either connect or disconnect (like flexing headphone wires after they broke). I'm glad you found the issue on your printer 🙂


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