@droftarts said in Duet3 Mini 5+ catches fire when micro USB is plugged in:

If you want to try and repair the voltage regulators, part numbers are here: https://docs.duet3d.com/en/User_manual/Troubleshooting/Parts#voltage-regulators

Thank you! I'm not averse to attempting a fix myself, I have all the equipment. Didn't wanna muck up the board any further though if you wanted it back for a trade in. I appreciate the resources and will consider it.

@dc42 said in Duet3 Mini 5+ catches fire when micro USB is plugged in:

Were the Duet PSU and the PC plugged into different wall sockets, or into a socket strip powered from the same wall socket?

They (desktop and printer) were plugged into two separate wall sockets across the room that are on the same circuit. This house was built with aluminum wiring and has several other electrical obscurities, so I wouldn't rule out something wrong with my mains wiring.

Also, I checked the neutral and ground connections and they are quite secure. I also hadn't ran the heater or anything, it was quite an immediate burst of flames when I plugged in the USB.

@Phaedrux Thank you very much, I really appreciate your assistance.

@Phaedrux said in Duet3 Mini 5+ catches fire when micro USB is plugged in:

Are you able to communicate with the board over USB terminal still?

Nope, not even recognized as a USB device

@Phaedrux said in Duet3 Mini 5+ catches fire when micro USB is plugged in:

You can go through this document to see how damaged the board is.

https://docs.duet3d.com/en/User_manual/Troubleshooting/Duet_wont_respond

Well, the only thing that lights up is the +5v when connected to micro USB, otherwise via a power supply it seems to be performing normally.

@Phaedrux said in Duet3 Mini 5+ catches fire when micro USB is plugged in:

You mean to say you had the board connected to a 12v or 24v power supply and USB at the same time?

Well, now that you mention it, that's obviously the case. I created a ground loop. I was used to RAMBo 1.4 where they both needed to be plugged in. When I worked with 3D printers at my old lab we always used laptop so it was never an issue we needed to be aware of. I'm making a home-built printer and was upgrading the motherboard with a mini 5+.

I bought the board from Filastruder on November 18th, as it was the cheapest I could find at the time for $140.

I was imagining the possibility of a workaround. I thought that I could load the gcode to connect to the wifi onto the micro sd and run it from there, but without a screen (I have an old reprap discount smart controller that from my research isn't supported), I don't know how to send it any commands for connecting to wifi.

I'll also add before I go; If I unplug the micro usb and turn it on normally the LEDS turn on like normal, indicating it isn't bricked or anything. However, with just the micro USB plugged in, the computer isn't recognizing it and it has one solid red LED. Unfortunately, I have no idea how I can get it to connect to wifi now.

This just happened so I haven't tried researching it at all. Really unhappy, not going to be able to use it in time for Christmas commissions like I had hoped.

I had the the board plugged in and powered on, and I plugged in the micro USB to my computer. Without researching the components clearly involved I have 0 idea as to what could have occurred (I'm going to sleep first I'll look tomorrow). I don't recall seeing anything that said I couldn't have both plugged in at once, it seems absurd if that is the case.