Help! Fan0 stopped working



  • Hi I really hope someone can help me. My Fan0 suddenly stopped working. When pwered up the Fan starts moving a bit and then stops. When measuring the Voltage it shows 24 V when activated and about 12 V but fluctuating when stiched off. The other Fans are working normal and when I connect the Fan to an allways on connector it works fine. Did I damage something and if yes what might it be. Is there a way to debug it?
    Thanks ahead!


  • administrators

    It sounds like a blown fan mosfet. Which Duet is it? What type of fan is it, and what are your M106 settings for Fan 0?



  • Thanks for the fast reply! The slicer handles it with M106 S0 and M106 S255 commands. Propably you are right 😕 Can you tell me which Mosfet I have to replace and provide a name oder link which would fit? I have some experience in SMD soldering.





  • If you have an unused PWM fan output, you can use the M563 Fn command (where n is the fan output number) in your tool definition to map the fan output to fan0 for that tool. Then plug in the fan to that output.

    That way your existing gcodes will still work with no modification.

    Probably also want to double check your wiring and connections are good. I've had the same issue happen to me and it appeared to be a short on the output wiring that blew up the driver.



  • Thanks for the link. In the description about how to replace a fan mosfet it sounds like a special handling is necessary... is there a reason not to just use a very thin solder iron to replace it?


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