Just shorted 5v rail for fan pins.



  • So I am having issues getting my 5v fan to power off of the 5v fan pins on the duet wifi.

    Upon testing to see voltage from the pins I lost balance and leaned and shorted the rail. The Duet will no longer connect to web control, or show the 3.3v or 5v leds on. Is there a certain component on the board I can replace or did I just fry my board?


  • administrators

    It sounds to me that something in the 5V regulator has failed. If you provide USB power, do the LEDs light up and can you connect?



  • I was too frustrated to try that. Hold on here.



  • Luckily yes it all still works! Awesome. So I need to apply an external 5v to the board? What amps should it draw?


  • administrators

    The board itself draws about 200mA average from 5V and probably about 300mA peak, but you need to add the current draw of any PanelDue, active endstops, or servos that are being powered from 5V or 3.3V.

    The 5V regulator on your board can probably be repaired. I expect either the regulator chip or one of the inductors has failed.



  • @dc42:

    The board itself draws about 200mA average from 5V and probably about 300mA peak, but you need to add the current draw of any PanelDue, active endstops, or servos that are being powered from 5V or 3.3V.

    The 5V regulator on your board can probably be repaired. I expect either the regulator chip or one of the inductors has failed.

    Okay awesome this is great news. I will take the board into work on Monday see if our electrical engineer can find the faulty component. Thanks!


  • administrators

    You can find the schematic for the Duet WiFi at https://github.com/T3P3/Duet/blob/master/DuetWifiv1.01/DuetWifi_Schematic_v1.01.pdf. My guess is that one of U3, L1 and L3 has failed.



  • I was looking at the schematic, and I wanted to just start from the beginning, and test the transistor at D1. But, I am unclear of the orientation of the transistor and do not want to risk shorting that either while testing. Do you know the orientation? Or a good reference site to read up on the super small component orientations? I see it has the vertical bar on one side but not sure what that relates to.


  • administrators

    Just look up the datasheet for that mosfet on Google. See the link in my previous response for the part number.


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