VSSA fuse?



  • I am pretty sure that I blew the VSSA fuse on the Duet 3D Wi-Fi v2. I was trying to upgrade a old Flsun i3 (really old Cartesian printer). I tried using the configuration tool, and all the motors were working fine.
    Turned my attention to fans and heaters, and wired everything. I wasn't really sure about configuration so I added the extruder as a tool. I heard a pop and smelled some smoke and now both the heater and extruder temperature show 2000°. In addition, the fans no longer work.
    From reading the discussions, it sounds like the VSSA fuse might be the problem. I don't think I'm capable of soldering (I am a quadriplegic). Of course, I plan on checking the resistance across the fuse, but is there anything I can do without soldering? I would like to get the extruder and fans to work, maybe the heated bed. Were there some minimum requirements for the thermistor, fan, or heating bed? I just plugged them in according to the diagram under "getting started."
    At this point, I think my caregivers would prefer I just buy a new assembled printer.

    I will take any advice.



  • The fans are probably a separate issue; if the always-on fan outputs also failed then check the 1A automotive fuse over by the Vin connector. If the fuse is OK then odds are the mosfets failed, with short circuits its often possible to see physical damage to the little transistors just by the fan headers, upload a picture for peer review is always an option.

    As for non-soldering fix for the VSSA fuse, you can run a wire (with an in-line fuse!) from a VSSA pin over to ground, either from an unused thermistor input, or tee off from one in use. But this would be best done with some crimped terminals at which point I'm not sure its any easier than soldering (pardon the ignorance here).

    One interesting approach is to just leave it a day or two as the VSSA fuse is made to reset itself (was news to me it could reset after so long, but aparently it does could). Sadly that is unlikely to have any effect on the fans having failed. When testing the VSSA fuse I think the nominal value should be about 2-3 ohm.

    Alternatively trying places like makerspaces or similar could be a place to get help. Depending on your location you may find some of this community nearby and willing to help on this rather short list: https://forum.duet3d.com/topic/13875/community-repairs



  • Thank you...I will take a look when I can and get pictures. Quad life... might be awhile.



  • @bearer said in VSSA fuse?:

    1A automotive fuse over by the Vin connector.

    bc09c78f-6ac3-4452-9c88-095ef510f992-image.png

    Where is it?

    Also, my caregiver could not get a steady VSSA reading... any tricks of the trade? alligator clips fall off...



  • ordered plunger minihooks. Should suffice.


  • Moderator

    Sorry to see you've experienced such a failure. It sounds like there was a short with the hotend wiring. Perhaps we can help out.

    If this is a genuine Duet purchased from an authorized reseller we may be able to provide a refurbished unit on exchange at reduced cost. Please send an email to roland@duet3d.com to inquire about availability. Please include a link to this thread.



  • @Phaedrux Wow, thank you! I will send an email.


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