what causes the fire ? (duet 3 mini 5+)

[Simon 4]

As I wanted to start the board for the first time I got immediately a plum of smoke.
fortunately I have an other one for spare. Because I did not find an error, does anybody know what could be my mistake, just by seeing the burned parts ?

https://drive.google.com/file/d/1w5gRHN3rzQCvHUkMhmuRr9kvEZYB0YJ1/view?usp=share_link
https://drive.google.com/file/d/1M73lVpZ6yPKgn_BZX48WWQSqlfX6u3jb/view?usp=share_link

edit:
just found a other burned part
https://drive.google.com/file/d/1FzXmBexCOqcAkS_YJjh61b3kfyzIXfXt/view?usp=share_link

board has a sticker on the back 202106-1283

sorry, pictures will not open automaticly. Is there a trick when using google drive ?

[dc42]

@Simon-4 it appears that the 5V regulator and 5V ESD protection diode have failed. I don't see anything in your wiring that would account for that. Please measure the output voltage of your power supply before you connect it to your spare board and let us know what you find.

When and where did you purchase the board?

[Simon 4]

@dc42 the board was purchased 1-2 month ago at Filafarm

link

due to your information I did a jumper on the "internal 5V disable" but it roasted the small chip 2 more seconds till total death.

thanks for help, I will use the other one instead

[dc42]

@Simon-4 please verify that your PSU is outputting the correct voltage before you connect the other board. If you can verify that, we will replace the failed board.

[Simon 4]

@dc42

that was the first I did, its a new meanwell 24V dc on the spot
The LAN version did start up correct without fumes, now I will add one external part after the other to detect potential failures.
As a note, I do not have any 5V part.

[T3P3Tony]

@Simon-4 please can you email warranty@duet3d.com with a link to this thread.